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Regional Oral History Office University of California 

The Bancroft Library Berkeley, California 

Arthur L. Schawlow 


With an Introduction by 
Boris P. Stoicheff 

Interviews Conducted by 

Suzanne B. Riess 

in 1996 

Copyright 1998 by The Regents of the University of California 

Since 1954 the Regional Oral History Office has been interviewing leading 
participants in or well-placed witnesses to major events in the development of 
Northern California, the West, and the Nation. Oral history is a method of 
collecting historical information through tape-recorded interviews between a 
narrator with firsthand knowledge of historically significant events and a well- 
informed interviewer, with the goal of preserving substantive additions to the 
historical record. The tape recording is transcribed, lightly edited for 
continuity and clarity, and reviewed by the interviewee. The corrected 
manuscript is indexed, bound with photographs and illustrative materials, and 
placed in The Bancroft Library at the University of California, Berkeley, and in 
other research collections for scholarly use. Because it is primary material, 
oral history is not intended to present the final, verified, or complete 
narrative of events. It is a spoken account, offered by the interviewee in 
response to questioning, and as such it is reflective, partisan, deeply involved, 
and irreplaceable. 


All uses of this manuscript are covered by a legal agreement 
between The Regents of the University of California and Arthur L. 
Schawlow dated May 3, 1997. The manuscript is thereby made 
available for research purposes. All literary rights in the 
manuscript, including the right to publish, are reserved to The 
Bancroft Library of the University of California, Berkeley. No part 
of the manuscript may be quoted for publication without the written 
permission of the Director of The Bancroft Library of the University 
of California, Berkeley. 

Requests for permission to quote for publication should be 
addressed to the Regional Oral History Office, 486 Library, 
University of California, Berkeley 94720, and should include 
identification of the specific passages to be quoted, anticipated 
use of the passages, and identification of the user. The legal 
agreement with Arthur L. Schawlow requires that he be notified of 
the request and allowed thirty days in which to respond. 

It is recommended that this oral history be cited as follows: 

Arthur L. Schawlow, "Optics and Laser 
Spectroscopy, Bell Telephone Laboratories, 
1951-1961, and Stanford University Since 
1961," an oral history conducted in 1996 
by Suzanne B. Riess, Regional Oral History 
Office, The Bancroft Library, University 
of California, Berkeley, 1998. 

Copy no. 

This photograph shows a flash of light from a ruby laser breaking a blue inner 
balloon without damaging the outer balloon. The red light from the laser 
passes through the clear outer balloon, but is absorbed by the dark blue inner 
balloon and produces a hot spot which breaks it. To show the balloon in the 
middle of the brief instant of breaking, a photographic flash lamp is 
triggered when the sound of the breaking balloon reaches a microphone. This 
gives a one millisecond delay after the laser pulse. 

Photograph by Kenneth Sherwin and Frans Alkemade 

San Francisco Chronicle, April 30, 1999 

Arthur Schawlow 

Arthur Schawlow, a Stanford Uni 
versity physicist and 1981 Nobel 
Prize winner for his pioneering work 
in lasers, died Wednesday at Stan 
ford Hospital after a prolonged ill 
ness. He was 77. 

Professor Schawlow and Charles 

Townes, professor emeritus of phys 
ics at the University of California at 
Berkeley and Professor Schawlow's 
brother-in-law, shared credit for in 
venting the laser, which made possi 
ble fiber-optic telecommunications, 
outpatient corrective eye surgery 
and CD music players, among many 

The two men developed the de- 
sign for the laser in the 1950s and 
built a working laboratory model in 
1960. But they never made any prof 
its from the discovery because they 
were working for Bell Laboratories 
at the time. Both men are in the 
Inventors Hall of Fame in Akron, 

A native of Mount Vernon, N.Y., 
Professor Schawlow was interested 
in electrical, mechanical and astro 
nomical things from childhood. He 
earned bachelor's and graduate de 
grees in physics from the University 
of Toronto. 

He met his collaborator, Townes, 
a recognized leader in the field of 
microwave spectroscopy at Colum 
bia University, while on a postdoc 
toral fellowship there. 

In 1961, Professor Schawlow 
joined the physics department at 
Stanford, where he continued his 
research in optical and microwave 
spectroscopy, superconductivity 
and lasers. He was popular among 

students for both his science knowl 
edge and his sense of humor. 

At Stanford^ Professor Schawlow 
was given the nickname "the laser 
man" because of his popular class 
room demonstrations of the way the 
new tool he had helped develop 

In a favorite illustration of the 
laser's pinpoint selectivity, he used 
what he jokingly called a "ray gun" 
laser to shoot through a transparent 
balloon to pop a dark Mickey 
Mouse balloon inside without 
damaging the outer one. 

Stanford physicist and Nobel lau 
reate Steven Chu recalled visiting a 
physics lab where "The Sayings of 
Art Schawlow" had been posted on 
a wall. One example: "To do suc 
cessful research, you don't need to 
know everything, you just, need to 
know one thing that isn't known." 

Professor Schawlow is survived by 
his son, Artie, of Paradise, Calif.; 
daughters Helen Johnson of Stevens 
Point, Wise., and Edie Dwan of 
Charlotte, N.C.; and five grand 

A memorial service is planned at 
Stanford University, but no date has 
been scheduled. 

Cataloguing information 

SCHAWLOW, Arthur L. (b. 1921) Physicist 

Optics and Laser Spectroscopy, Bell Telephone Laboratories, 1951-1961, and 
Stanford University since 1961, 1998, x, 383 pp. 

Schawlow family background, Depression years in Toronto; early aptitudes in 
radio engineering; college and university studies in math and physics, and 
WWII interruption; Malcolm Crawford and thesis research on atomic beam light 
source; post-doc at Columbia University, 1949-1951; co-author, with Charles H. 
Townes, of Microwave Spectroscopy (1955), dealing with theory and experimental 
techniques of microwave Spectroscopy; marriage in 1951 to Aurelia Townes, and 
move to Bell Telephone Laboratories: working on superconductivity, in 1957- 
1958 collaborating with Townes on the optical maser (laser), and publication 
of "Infrared and Optical Masers"; discussion of the atmosphere at Columbia and 
at Bell Labs, pressures, publications, patents; joins physics faculty at 
Stanford University: research group in laser Spectroscopy, Ted Hansch, 
students, administrative matters, other faculty; interest in teaching, 
motivation, ethical issues, funding and the military, telling stories, timing, 
hindsight; expert jazz collector; Nobel Prize in Physics, 1981, and other 
honors; son Arthur, Jr., and discussion of the treatment of autism. 

Introduction by Boris P. Stoicheff, Department of Physics, University of 

Interviewed 1996 by Suzanne B. Riess. 

TABLE OF CONTENTS --Arthur Schawlow 

INTRODUCTION by Boris P. Stoicheff i 




Schawlow Family, Toronto Childhood 1 

Religious and Cultural Milieu 7 

Early Interest in Engineering and Science 10 

High School, Vaughan Road Collegiate Institute 16 

Some Beliefs, and Some Disbeliefs 19 

Entering College, University of Toronto 23 

Physics in the Prewar and War Years 27 

Radio, Scouting, and Jazz Music 31 

Seeing the Possibilities in a Career in Physics 38 

Thoughts on Emigre Physicists, and Family Support 42 

Graduate School YearsThe Master's Degree 45 

Research Enterprises Ltd., Wartime Research, the Bomb 50 

Graduate School YearsAtomic Beam Light Source 56 

Crawford and Welsh, and Women Students 66 

Hindsights 68 


Carbon and Carbide Fellowship 72 

Charles Townes and the Microwave Spectroscopy Book 76 

Meeting and Marrying Aurelia Townes 80 

Theoretical Work, and Publishing on Hyperfine Structure 83 

The Atmosphere at Columbia, 1949 85 

Publications and Timing 87 

Seminars and Group Meetings 89 

Looking for OH 91 

The Subject of Equipment 94 

Nepotism Necessitates a Job Search 96 

More on Writing the Microwave Book with Townes 98 


Experiments on Superconducting Phenomena 102 

Research, Resources 107 

Murray Hill, and the Work Day 110 

Madison, and Home Life 113 

Stan Morgan and the Solid State Group 115 

Working up to the Laser 120 

Mode Selection 124 

About the PatentThe Smell of Success 127 

Looking at MaterialsRuby 130 

Ted Maiman's Work, and Publication 135 

Pressure Results in Exhaustion, 1960 141 

Publishing with Bell Labs The Clad Rod Laser 144 

Time to Leave Bell Labs 146 

National Inventors Hall of Fame, 1996 150 

Laser Action in Ruby- -Physical Review Letters Feb. 1, 1961 152 

Inventing Stuff 156 

Science Writers, Informing the Public 158 

Post-Laser Atmosphere at Bell Labs 160 

Gordon Gould and the Competitive Drive 161 

The Department, Plain and Applied 168 
Felix Bloch, Robert Hofstadter, Bill Fairbank 170 
And SLAG 172 
The Big Picture: Teaching, Labs, Students, Postdocs 176 
And Administration: Department Chair, 1966-1970 180 
The Family 187 

Settling into Palo Alto 187 

Autism and Artie 188 

Helen and Edith 200 


Secrecy, Motivation, and Morality 209 

Uses of the Laser, Unusual and Medical 213 

Funding and the Military 217 

Facilities at Stanford 222 

"Science in Action" and Other Honors 226 

Some Russian Physicists 229 

People and Projects 233 

Optical Science 233 

Mollenauer, Imbusch, Emmett, McCall 234 

Titanium in Ruby Rods 239 

Light-controlled Chemical Reactions 241 

Consultancy at Varian 243 

The Hodgepodge of Projects, Ray Gun, Full House in the Lab 244 

Fortunate Conjunction 248 

Travelling 248 

Ted Hansch, and Edible and Tunable Lasers 250 

Doppler-free Spectroscopy 252 

Brillouin Scattering: Marc Levenson 254 

R.R. Donnelley Co. Project in Switzerland 255 

Cooling with Laser Light, and Other Good Ideas 256 

Tower of Babel 258 

More on Laser Cooling 260 


General Look at How Schawlow Works 263 

Prize-Winning Work: Rydberg Constant 267 

Quantum Electrodynamics 269 

Hyperfine Structure of Iodine 273 

The Apostolic Succession Phenomenon 275 

National Ignition Facility Work, and the Military Sponsorship 276 

Work and Publications with Students 277 

Chinese Physics Graduates 282 

Summing up the Seventies 285 

News of the Nobel PrizePutting the Money to Work for Artie 287 

Current Work 291 

Thinking in Classical Pictures 293 

A Few Last Stories to Tell 294 



A Publications 302 

B Four pages excerpted from Toronto Jazz, A Survey of Live 

Appearances and Radio Broadcasts of Dixieland Jazz Experienced in 
Toronto During the Period 1948-1950, by Jack Litchfield. 316a 

C "From Maser to Laser", by Arthur L. Schawlow, in Impact of Basic 
Research on Technology, Kursunoglu and Perlmutter, editors, Plenum 
Press, New York-London, 1973. 317 

D "Masers and Lasers", by Arthur L. Schawlow, Fellow, Institute of 
Electrical and Electronics Engineers, from IEEE Transactions on 
Electron Devices, Vol. ED-23, No. 7, July 1976. 354 

E "Never Too Late, Communication With Autistic Adults", by Aurelia 
T. Schawlow and Arthur L. Schawlow, in Proceedings of the NSAC 
(now Autism Society of America) National Conference, July 1985. 361 

F "Our Son: The Endless Search for Help," by Aurelia T. Schawlow and 
Arthur L. Schawlow, in Integrating Moderately and Severely 
Handicapped Learners, Strategies that Work, Brady and Gunter, 
editors, Thomas Books, Springfield, Illinois, 1985. 370 

INDEX 383 

INTRODUCTION by Boris P. Stoicheff 


The many contributions to science of Arthur Leonard Schawlow as a 
teacher, science writer, and creative physicist have won for him a 
renowned national and international reputation, highlighted by the award 
of the Nobel Prize in Physics in 1981, and the National Medal of Science 
in 1991. Two prestigious Arthur L. Schawlow Awards, given annually, 
honour him as one of the laser pioneers: a Medal of the Laser Institute 
of America for laser applications, and a Prize of the American Physical 
Society for contributions to laser science. On a more personal note has 
been the adulation of his many students and co-workers who published a 
volume, Laser Spectroscopy and New Ideas: A Tribute to Arthur L. 
Schawlow, on his 65th birthday in 1986, and who also organized The 
Arthur Schawlow Symposium on his retirement five years later. These 
were heart- felt gatherings of the many people whom he had touched with 
his friendship, consideration, and joy and wonder of science. 

Arthur was born in Mt. Vernon, New York, but his family moved to 
Toronto, Canada in time for him to take his primary and secondary 
education there. His sister Rosemary recalls that Art had some problems 
in early school. In fifth grade, one of the teachers made life 
miserable for Art in public school, so that the family was advised to 
register him at another school, the Normal Model School where teachers 
were being trained. His progress was very good in everything but 
writing and art. Under a teacher's pressure, his writing improved, but 
his clumsy hands, by his report, were no good for drawing. When he 
proceeded to high school, at Vaughan Road Collegiate, to avoid art he 
enrolled in bookkeeping and typewriting rather than in art and botany. 
Nevertheless, he was in the academic stream and took the other usual 
subjects for university entrance. Art graduated with an excellent 
record, and enrolled in one of the most demanding programs of 
Mathematics and Physics at the University of Toronto. Thus began his 
career in science. He continued in graduate studies, obtaining a Master 
of Arts degree, followed by his Ph.D. degree in atomic physics in 19A9, 
under the supervision of Professor Malcolm F. Crawford. 

It was in 1948, when I began graduate research at Toronto, that I 
first met Art. His experiment in atomic beam spectroscopy and hyperfine 
structure was located in the basement of the McLennan Physical 
Laboratory, where he spent most of the day with his co-workers Fred 
Kelly and Mac Gray, while I was with the molecular group on the fourth 
floor. This was an extremely active period, with many returned 
veterans, all working furiously to all hours of the night. We would 
meet at tea time and at colloquia. And once experiments were in 


progress, we seemed to have time to visit each other's labs because 
photographic exposure times were tens of hours, since this was the 
traditional method for detecting and recording spectra in those early 
years. It was a special pleasure to visit the basement lab, where often 
in the evenings Art would be serenading his atomic beam with the 
clarinet, which he played reasonably well. His idols were Benny Goodman 
and "Jelly Roll" Morton, and his repertoire mainly Dixieland jazz. 

By that time, Art had an enviable collection of jazz records. He 
and his sister Rosemary started collecting while in high school, by 
buying used juke box records. This expanded to a full fledged hobby 
later when he was better able to afford this pastime, and also to record 
the music himself as tape recorders became available. As his science 
progressed, he was able to travel to conferences in various cities, and 
to devote some evenings to music halls and jazz. 

Art and his colleagues published seven papers on their doctorate 
research including details of their apparatus and spectroscopic results. 
While each member of the team was responsible for designing and building 
an important part of the equipment and seeing to its proper working in 
the experiment, they each became acquainted with every piece of 
apparatus in the experiment. This turned out to be important to Art's 
later basic contribution to the laser; the two end mirrors which form 
the resonator are an adaptation of a device (the Fabry-Perot 
interferometer) used in the atomic beam experiments in the McLennan 
Laboratory. Art achieved early recognition for his research in atomic 
spectroscopy and received a postdoctoral fellowship to work at Columbia 
University. There began his long and fruitful association with Charles 
H. Townes, a pioneer of microwave spectroscopy, whom he first met at an 
American Physical Society meeting in April 1949. 

At Columbia University, Art began research on the diatomic 
molecule OH using the new technique of microwave spectroscopy, and 
having difficulty in finding its spectrum he coined the memorable line, 
"a diatomic molecule is a molecule with one atom too many." He also 
began writing with Townes the book titled Microwave Spectroscopy, one of 
the first volumes in this field. Just about that time, Townes was 
involved with development of the MASER, and he tells the following story 
of how the idea of the MASER occurred to him. In April of 1950, he and 
Art were attending an American Physical Society Meeting in Washington, 
D.C., and they shared a room in the Franklin Hotel. Art, being a 
bachelor, was used to sleeping late, and Charlie, being married with 
four young daughters, would be up very early. So, waking up early as 
usual, and not wanting to disturb Art, Charlie dressed and went out to 
nearby Franklin Park. It was there, sitting on a bench, thinking about 
a government committee meeting he would be attending that afternoon on 
trying to find better ways of producing radiation shorter than 
millimeter wavelengths, that the idea of the MASER hit him. As Art 


likes to point out, his own inadvertent contribution was crucial: 
"Imagine the result if I had wakened early!" 

In May 1951, Art married Aurelia Townes, Charlie's younger sister, 
a fine musician and vocalist, and they raised a family of a son and two 
daughters. In the fall of that year, Art was employed by Bell Telephone 
Laboratories in Murray Hill, New Jersey and carried out research in 
superconductivity. His contacts with Townes continued, as Art spent 
many a Saturday at Columbia completing the book, Microwave Spectroscopy, 
published in 1955, and Townes was consulting for Bell Labs. Their 
collaboration on the possibility of extending the range of the maser 
into the visible region culminated in their famous paper of December 
1958, "Infrared and Optical Masers," which established the principles of 
the LASER. Within two years, the first working device, the pulsed ruby 
laser, was developed by Theodore Maiman at Hughes Research Laboratories, 
soon followed by the helium-neon laser introduced by Ali Javan and 
colleagues at Bell Labs, and the era of the LASER was launched. The 
laser spawned a flourishing new field of science and technology, now 
known as "Quantum Optics", and a huge industry, commonly called 
"Photonics and Electro-Optics." And over the years, Art has been a 
continual contributor to the imaginative use of the laser in science, 
communications, engineering, and medicine. 

With his appointment as Professor of Physics at Stanford 
University in 1961, Art became a major influence in the lives of many 
young scientists. In no time, he gathered around him a large group of 
able students, and a constant stream of visitors from many countries 
soon followed. His students enjoyed the fatherly advice given with 
Art's usual sense of humour and understanding: "To do successful 
research, you don't need to know everything, you just need to know of 
one thing that isn't known"; and, "Anything worth doing is worth doing 
twice, the first time quick and dirty, and the second time the best way 
you can." And when science fiction writers and journalists wrote about 
the death ray, and produced posters of "The Incredible Laser", showing 
laser cannons firing at rockets, Art's answer was that all one had to do 
was to polish the outer surfaces to reflect back the beam of light. In 
his own laboratory, he mounted such a poster on the door, adding the 
subtitle, "For credible laser see inside." In this heady atmosphere 
with its special "magic", the Schawlow Laboratory was one of the 
outstanding contributors in laser spectroscopy, producing many new ideas 
and techniques which became standards in the field. 

During this early period of the laser, Art was deluged with 
invitations to write articles for the lay public, and to lecture to a 
variety of audiences all over the world. He accepted an exhausting 
schedule of travel, and charmed and informed audiences with his 
characteristic flair for telling anecdotes and performing 
demonstrations. One of his favourite and most vivid lecture 
demonstrations was to use his portable "ray-gun laser" to burst a blue 


Mickey Mouse balloon placed inside a clear outer balloon, without 
damaging the outer balloon. This same idea had important consequences 
since it was applied to remedy retinal detachment with the laser: the 
lens of the eye transmits the red laser light, but the retina absorbs it 
and is heated sufficiently to weld the retina together. Art found the 
requisite balloons in the San Francisco Zoo, which he visited each month 
to stock up on his supply. One Sunday, when parents with disappointed 
children questioned the Sold Out sign for double balloons, they were 
told by the proprietor, "A crazy professor just bought out the entire 
stock!" Some demonstrations were carried out without apparatus, as when 
Art reminded audiences of the Doppler Effect, and moving towards the 
audience he elevated the pitch of his voice, and moving away he lowered 
the pitch. 

Art's ad libs at seminars and colloquia are legendary. On one 
occasion he was speaking at Stanford on the topic, "Is Spectroscopy 
Dead?" He immediately defined what he meant by spectroscopy, and 
proceeded to give his talk, when Professor Felix Bloch asked, "What do 
you mean by dead?" Art blurted out, "Oh, when the chemists take over," 
to which he added his infectious laugh, and everyone else joined in, 
although chemists in the audience were not amused. Of course, Art went 
on to say that that was what happened to microwave spectroscopy, now 
done mainly by chemists and few physicists, so that chemists know much 
more about molecules. I vividly remember when he introduced me at a 
Stanford colloquium, and having given a brief biography, stressed that 
my undergraduate and graduate degrees were from the University of 
Toronto, and then emphasized, " he is very well-educated," followed 
by his belly-shaking laugh, knowing full well that his Stanford 
colleagues were aware that he too studied at Toronto. In Art's case, we 
added an Honorary Doctorate Degree in 1970 to make a total of four 
degrees from the University of Toronto, and branded him an "Exceedingly 
well-educated man." 

Among Art's later contributions to science, two carried out with 
Ted Ha'nsch, then his colleague at Stanford, stand out. One was 
seemingly frivolous, and related to Art's contention that "anything will 
lase if hit hard enough." They experimented with various flavors of 
Knox Jello in an effort to make an "edible laser." Finally, they added 
sodium fluorescein to clear gelatin and, lo and behold, when pumped by 
an ultraviolet laser, green laser light was produced. Later, colleagues 
at Bell Labs used gelatin film to demonstrate the first "distributed 
feedback laser", a form of laser which today plays an important role in 
optical communications. The second contribution was the seminal idea of 
cooling gas atoms by laser radiation pressure. This method was 
developed at several laboratories and used to cool gas atoms to almost 
absolute zero, leading to the award of the 1997 Nobel Prize in Physics 
to three of their friends, Steven Chu at Stanford, Bill Phillips at 
NIST, and Claude Cohen-Tannoud j i in Paris. 

Along with these many scientific successes and accolades, Art and 
Aurelia lived graciously with a heart-rending sadness, the care of their 
nonverbal autistic son, at home and later at medical institutions. 
While in Sweden, at the time of the Nobel Award, Art learned of a hand 
held communicator, and with that device and special calculators they 
were able to improve communication with their son. Art and Aurelia 
later helped to organize a nonprofit corporation, California Vocations, 
a group home for autistic people. A further tragedy was the death of 
Aurelia in 1991, while on her way to visit their son, living about two 
hundred miles from Palo Alto. 

It has been my good fortune to also work in laser spectroscopy, 
and to keep in close contact with Art Schawlow over the years. He has 
been a valued friend and inspiration, and one constantly remembered for 
helping to bring to the world "A Wondrous New Light." 

Boris P. Stoicheff 

University Professor of Physics, Emeritus 

April 1998 
Toronto, Ontario, 

INTERVIEW HISTORY- -Arthur Schawlow 

Arthur Schawlow, winner of the Nobel Prize for Physics in 1981 for 
his contributions to the development of laser spectroscopy, and a 
Californian since 1961, is a stellar member of the group of fine 
scientists, in particular physicists, who came west in the sixties, often 
redirecting their research focus at mid-life. Leaving behind a career that 
had been centered at Bell Telephone Laboratories, Professor Schawlow chose 
to bring his work and his family to Stanford University. There he taught 
and took on administrative responsibilities, and with his students and his 
colleagues completed major research that has advanced the knowledge and 
applications of laser science and spectroscopy. 

This brief interview history will not summarize Arthur Schawlow 1 s 
achievements. Boris P. Stoicheff has done that very well in the 
introduction he has graciously contributed to the memoir. A two-page 
biography, extensive bibliography, and other documents appended demonstrate 
the range and extent of the scientific pursuits and publications of 
Professor Schawlow. It is assumed that an historian of science will refer 
to Professor Schawlow 1 s writings for a more precise chronology of the 
development of laser spectroscopy. 

In undertaking to conduct an oral history with Arthur Schawlow it was 
my particular ambition to articulate the excitement and energy of moments 
of discovery, the life of the laboratory, and the total commitment to the 
work that informs the science of Arthur Schawlow. All that, as well as to 
get onto paper his humor and rare personal qualities. And I was not alone 
in such an ambition. 

The reason Professor Schawlow agreed to the request of the Regional 
Oral History Office to do an oral history, to take the time, and to summon 
up the emotional fortitude often required for the interviews, as well as 
the time for checking and editing, was because for him the manner in which 
one puts the point across is keenly important to the story, whether in 
talking to the interested general public or his students or his peers. He 
wanted to illustrate the pleasures of his profession. He had begun to 
write an autobiography, and he felt that doing an oral history would 
facilitate that writing. 

My first encounter with Professor Schawlow was through interviewing 
Charles H. Townes. Arthur Schawlow wrote the introduction to the 1995 
Townes oral history, A Life in Physics: Bell Telephone Laboratories and 
World War II; Columbia University and the Laser; MIT and Government 
Service; California and Research in Astrophysics. The two men are 
colleaguesoriginally Schawlow was a graduate student at Columbia working 
with Townes--and they are co-authors, and related through marriage. That 
rare combination of relationships is very strong. 


Here is what Schawlow wrote in his introduction to Townes: "It was 
Frances Townes [the wife of Charles Townes] who made sure that I became 
acquainted with Charles' younger sister, Aurelia... Although everything I 
have done in physics since then has been enormously aided and influenced by 
what I learned from Charles Townes, I have to say that meeting Aurelia was 
the best thing that happened to me in New York." That quote, with its 
underlying humor, is not hyperbole. 

However, as the reader will learn, the life that Arthur and Aurelia 
Schawlow shared required far more than the usual wedded commitment because 
of the sad and very difficult practical family problem for them, and their 
daughters, of the quality of the life of their severely autistic first 
child, their son, Arthur, Jr. This issue is discussed fairly openly in the 
oral history. It is still very emotionally charged, very present, and it 
requires much of Professor Schawlow 1 s time. The death in an automobile 
accident in 1991 of his wife Aurelia doubled his responsibility for his 
son, and dimmed the light of his life. 

The oral history interviews began with my first meeting Professor 
Schawlow at his two-room apartment in Palo Alto. From there we set off in 
his car to his office at Stanford. I was immediately struck by the sheer 
amount of technology he surrounded himself with. Both locations were 
replete with computers, terminals, hookups, cables and tables, and books. 
It came as no surprise that he was adept with this technology, and that his 
office was bristling with it, but the fact that he lived so much in its 
midst at home was striking. 

Equally striking, and completely delightful, was the mitigating 
presence of an impressive jazz music tape and CD library lining his living 
room walls. The sound of music leavened the table- top technology. After 
our two-hour morning interview sessions were finished sometimes I would be 
treated by Professor Schawlow to a particularly choice musical interlude, 
always jazz, perhaps taped from a live performance using clever, sensitive, 
and pocket-sized equipment! I was the recipient of the gift of two of the 
best tapes, technically, that anyone has ever made for me, and I listened 
to Bob Crosby's band as I drove between Berkeley and Stanford for our eight 
interviews, from August to November, 1998. 

Doing an oral history, delving into the past, reviewing struggles and 
successes and looking at causes and outcomes, usually amounts at the very 
least to a diverting experience for the interviewee. However, I would say 
that our interviews, productive and pleasant as they very definitely were, 
could not distract from a feeling of a the missing center and balance in 
Professor Schawlow' s life in 1996. He had only just moved from the 
Schawlow' s family home in Palo Alto to a retirement community. Limited 
space, social readjustments, and relearning the bachelor life after long 
married yearsdealing with such household practicalities as acquiring a 
sink big enough to wash a pot inthis stuff challenged Arthur Schawlow' s 
natural good humor. 


Having said all that, it was also manifest that Professor Schawlow 
was not disappearing into retirement. During our interviews he was and 
certainly continues to be much in demand. Attending meetings and what 
appears to be an endless cycle of award presentations kept him flying more 
than he would have wished. Yet when it came time to edit the transcripts 
that I had reviewed and organized with chapter headings, Professor Schawlow 
was very responsive to my queries, meticulousnot changing the text, but 
clarifying the meaning. If there are any errors in the oral history it is 
our fault, not his. 

Laser, spectroscopythese words are associated with intense, bright 
searching light, healing light, measurement, the furthering of knowledge. 
The reader will meet a man who has contributed his life to the search, and 
get a good sense of how he thinks, how he picks his problems, how he goes 
about solving them, and how he delights in the challenge. 

The Regional Oral History Office, a division of The Bancroft Library, 
was established in 1954 to record the lives of persons who have contributed 
significantly to the history of California and the West. Other oral 
histories in science and technology are available through the Office, which 
is under the direction of Willa K. Baum. 

Suzanne B. Riess 
Interviewer /Editor 

May 1998 



Arthur L. Schawlow was born in Mount Vernon, New York. He received the 
Ph.D. degree from the University of Toronto in 1949. After two years as a 
Postdoctoral Fellow and Research Associate at Columbia University he became a 
Research Physicist at Bell Telephone Laboratories. In 1960, he was a 
Visiting Associate Professor at Columbia University. Since 1961, he has been 
a Professor of Physics at Stanford University. He was Chairman of the 
Department of Physics from 1966 to 1970; Acting Chairman, 1973-74, and in 
1978 was appointed J.G.Jackson and C.J.Wood Professor of Physics. 

His research has been in the field of optical and microwave 
spectroscopy, nuclear quadrupole resonance, superconductivity, lasers, and 
laser spectroscopy. With C. H. Townes, he is coauthor of the book, 
Microvave Spectroscopy, and of the first paper describing optical masers, 
which are now called lasers. For this latter work, Schawlow and Townes were 
awarded the Stuart Ballantine Medal by the Franklin Institute (1962), and the 
Thomas Young Medal and Prize by the Physical Society and Institute of Physics 
(1963). Schawlow was also awarded the Morris N. Liebmann Memorial Prize by 
the Institute of Electrical and Electronics Engineers (1964). 

Dr. Schawlow received a Nobel Prize for Physics in 1981 for "his 
contribution to the development of laser spectroscopy." 

Schawlow was named California Scientist of the Year in 1973. In 1976, 
he was awarded the Frederick Ives Medal of the Optical Society of America "in 
recognition of his pioneering role in the invention of the laser, his 
continuing originality in the refinement of coherent optical sources, his 
productive vision in the application of optics to science and technology, his 
distinguished service to optics education and to the optics community, and 
his innovative contributions to the public understanding of optical science." 
In 1977, he was awarded the Third Marconi International Fellowship. Schawlow 
also received a Golden Plate Award from the American Academy of Achievement 
in~1983. In 1991, he received a U.S. National Medal of Science for "his role 
in the conception of the laser and advancing its applications, particularly 
to laser spectroscopy." 

In 1982, the Laser Institute of America established the 

Arthur L. Schawlow Medal for laser applications, to be awarded annually. The 
first medal was awarded to Schawlow "for distinguished contribution to laser 
applications in science and education." The American Physical Society 
established the Arthur L. Schawlow Prize for laser science in 1990. In 1996 
he became a member of the American Inventors Hall of Fame, and also received 
the Ronald H. Brown American Innovator Award from the U.S. Department of 
Commerce. He also received the Arata Award of the Japan High Temperature 

He has received honorary doctorates from the University of Ghent, Faculty 
of Science, Belgium, 1968; University of Toronto, Canada, 1970 (Ll.D.); 
Bradford University, England, 1970 (D.Sc.); University of Alabama, USA, 1984 
(D.Sc.); Trinity College, 1986, Ireland (D.Sc.); University of Lund, Sweden, 
1988 (D.Tech.): Victoria University, Toronto, Canada D.S.L. (1994). He is an 
Honorary Professor of East China Normal University (1979) . 

Schawlow is a Fellow of the American Physical Society (Member of 
Council, 1966-1969), the Optical Society of America (Director-At-Large, 
1966-1968), the Institute of Electrical and Electronics Engineers, the 
American Association for the Advancement of Science, the American Academy of 
Arts and Sciences, the American Philosophical Society, the Institute of 
Physics (Great Britain), and a Member of the U.S. National Academy of 
Science. He was Chairman of the Division of Electron and Atomic Physics of 
the American Physical Society (1974), President of the Optical Society of 
America (1975), and Chairman of the Physics Section of A.A.A.S. (1979). He 
was President of the American Physical Society in 1981. He was Chairman of 
Commission C.15, Atomic and Molecular Physics (1978-1981), and Chairman of 
the U.S. National Committee for the International Union of Pure and Applied 
Physics (1979-1982) . In 1983 he was elected one of six Honorary Members of 
the Optical Society of America. He is an Honorary Member of the Gynecologic 
Laser Society and of the American Association for Laser Medicine and Surgery. 
He is also an honorary member of the Royal Irish Academy (1991). 

Dr. Schawlow wrote the introduction for Scientific American Readings on 
Lasers and Light, and three of the articles in that collection; he is author 
or coauthor of over 200 scientific publications. On television, he has 
appeared on one of the 21st Century programs with Walter Cronkite, and one of 
the Experiment Series with Don Herbert, as well as on films for Canadian, 
British, Japanese, and German T-V networks. 

April, 1998 


[Interview 1: August 14, 1996] II 1 

Schawlow Family, Toronto Childhood 

Riess: Please start in at the beginning and tell me what you can about 
your parents. You said last time that you didn't know that 
much family history, but you'll want to include what you can 

Schawlow: Yes. I was born in Mount Vernon, New Yorkand my birth 

certificate says so--on May 5, 1921. We didn't live there very 
long: my parents moved, I understand, to New Rochelle, and then 
when I was about three years old, they came to Toronto, Canada. 

My mother was born in Canada, grew up there, and she never 
wanted to talk much aboutneither of my parents wanted to talk 
much about their early life. I think it was a fairly large 
family, because occasionally we'd meet a brother or sister 
who'd come to town and visit. But she claimed that her father 
was a mounted policeman at one time. I talked with a cousin 
who claimed that they were all farmers. I don't know. She 
said she was born in Petacodiac, British Columbia, which is a 
small town, which might have been a place where a mounted 
policeman would be living, but she grew up in Pembroke, 

I think that her mother died when she was born, and her 
father died about six years later. I think he remarried, but 
then after he died the family was broken up, and she lived with 
various people at various times, sometimes with her sister 
Mary, and that was not happy at all. Mary was an older sister, 
considerably older. She spent some time in a convent school. 
I think their family was Catholic, but she wasn't by the time I 

'II This symbol indicates that a tape or segment of a tape has begun 
or ended. A guide to the tapes follows the transcript. 

met her [laughter] --knew her, rather, 
about her. 

So I don't know much 

Cecilia lived in Pembroke; we knew her then, and she was my 
mother's favorite sister. Cecilia made wonderful doughnuts, I 
remember. And she had a son, Heber, who was about my age. We 
visited them in Pembroke a few times, and had a very pleasant 

During the war, Cecilia's husband, Percy Jessup--her 
married name was Jessup--was a plasterer. But he moved to 
Toronto and I think he had a job as a guard or something at a 
war plant, and then he died. They lived in the outskirts of 
Toronto for some time. My mother had another brother, Dan 
both of these were considerably olderand Dan worked in a 
transformer factory, General Electric Transformer. He was a 
millwright; I didn't know what that meant, but I think now it 
means a man who moves things around the mill, does the heavy 
moving. He was a bachelor for a long, long time and he used to 
come to Sunday dinner very often, and he'd usually bring a 
brick of ice cream. That's the way ice cream came in those 
days, usually from a drug storethat was the only place that 
was open on Sunday the ice cream was in bricks. 

Riess: How did your mother meet your father? 

Schawlow: Well, it's a rather mysterious thing. On my birth certificate 
her name is listed as Helen Mason, and her brother's last name 
was Carney. But I think some of the other brothers, younger 
brothers or half-brothers, are named Mason. So I don't know 
how that happened. But at any rate, I think for a while she 
worked as a practical nurse or assistant to nurse. Then she 
went to New York, I think to work with somebody there as a sort 
of nursing assistant. During the war, Metropolitan Life 
Insurance Company was very short of help and I think she worked 
with them, and that's how she met my father. 

My father had come from Latvia. He was born in Riga, and I 
don't think he was legally in the United States or, for that 
matter, in Canada. 

Riess: Was he an ethnic Latvian? 

Schawlow: He was Jewish. We didn't know it at that time. He didn't tell 
us until we were grown up. There was a lot of anti-semitism in 
Toronto. I don't think there were any Jewish professors. So 
my mother brought us up as Protestants in the United Church of 
Canada, which was formed in 1925, I think, as a union of the 
Methodists, Congregationalists, and half the Presbyterians the 

more fundamentalist Presbyterians continued as the Presbyterian 
Church. We were brought up as Christians, and I didn't know my 
father was Jewish. I don't think he was really religious, but 
his background was. And he didn't tell me until I was about 
seventeen or something like that. 

Riess: What was the occasion for telling you? 
Schawlow: I don't remember exactly, but he did tell me. 

Riess: When I ask about being an ethnic Latvian, the Latvian culture 
is very strong, and full of traditions. I wondered if he had 
any of that . 

Schawlow: Well, it's hard to tell. He certainly didn't show it. I think 
there were a number of people in the Baltic states who were of 
Germanic origin, and particularly Jewish people, and they 
probably behaved more as German Jews than as Latvians . But 
this is conjecture. He told us various stories when we were 
little, which I didn't believe, like he said he came from 
Georgia and then he talked later about skating across the ice 
to go to school. [laughs] Well, that didn't fit together, but 
somehow I had more respect for my parents and I didn't question 

Riess: Was he humorous? 

Schawlow: Yes, at times. He worked very hard. 

Let's go back into his history, what I know. He certainly 
had some mathematical ability, and he wanted to be an engineer. 
So he went to Darmstadt in Germany to study, and he got there 
too late for the start of the term, so he went on to visit one 
of his brothers in the United States. He, too, had a large 
familythis was the only one of his brothers I ever saw, his 
brother John, whose name was Schwartz. I'm told that there was 
some kind of a scandal and he changed his name . He ran a 
tobacco store and news store in Lambertville, New Jersey. Some 
of them changed their names: one's a Shaw, somebody's a Low, 
and I think there's even a brother in South Africa. There was 
one in Baltimore--! have my father's watch, a gold pocket watch 
which says "Welcome to Baltimore," and I think it's dated 1910 
or something like that. 

Riess: Schawlow was the original. Your father kept the name. 

Schawlow: Yes, I have his birth certificate, which is in Russian, 

actually. Latvia was controlled by Russia in those days. It 
was only free for a while between the wars, I think, and then 
again recently. 








So he came to visit his brother since he couldn't matriculate. 

Yes, that's right. And then he got this job with the insurance 
company, and that's how he met my mother. 

As I say, I don't think he was really legally in the United 
States. Coming to Canada, they told me at one point that you 
couldn't come with a job, it wasn't allowed. So he resigned 
from Metropolitan Life. Then after he got to Canada the 
resignation was declined, so he was able to go back to work for 
Metropolitan Life Insurance. He was very good, he was one of 
their top people in the office. He at one point was an 
assistant manager. 

You said that he had mathematical abilities, 
was using in his job? 

This is what he 

Well, I don't think he could use very much of it. It was a 
horrible job. He had to go out every night to collect, because 
the basis of the Metropolitan Life Insurance Company, which at 
that time was the largestit was so-called industrial 
insurance, which was weekly premiums for the working man. He'd 
go out and kind of collect a quarter here, a nickel there. 
Particularly during the Depression, it was very hard. But he 
never lost his job and managed to scrape through. And we never 
felt poor. We sort of knew what we could do, and we were 
always well-fed and clothed. 

It sounds like both parents, in a way, made a move that denied 
their religious background, and a lot of their background. I 
think that would be hard for them. 

Yes, I suppose so. I think it must have been, although we 
never really did get to discuss it. 

And your sister is older than you? 

Yes. I like to joke that I was named after my sister, about a 
year and a half after. [laughter) 

That's cute. 

She's tired of hearing that. Her name is Rosemary Wolfe. Her 
husband was a professor of geography at York University in 
Toronto. He's been retired for some years, and they still live 
in Toronto. She got a bachelor's degree in English literature 
and got a master's degree, and then later went back and got a 
library degree and worked for a while in libraries and for a 
while in bookstores. But she hasn't worked for a long time. 



What are your earliest memories? 
Vernon at all? 

Do they go back to Mount 



No. I understand that when we came to Toronto we briefly had 
an apartment or a flat or something on Pape Avenue, but I don't 
really remember that at all. 

What avenue? 

P-A-P-E. Then we moved to 408 Sackville Street, but we weren't 
there very long because most of the time we were there it was 
at 436 Sackville Street. We lived there until I was eleven. 
Just about when I was going into high school, my father moved 
to a different office, which was then on the edge of town 
actually in York Township, which was a separate municipality. 
There is now a metropolitan government. 

Reading the autobiography that you've written, I wondered 
whether you ended up with a sense of moving around all the time 
and uprootedness? 1 

Well, a little of that, yes. This early stuff didn't make much 
impression on me, I was too young. But moving to the suburbs 
was hard. I had a very close friend next door, Gordon Kendall, 
and it was a sort of wrenching experience. We would talk very 
frequently on the phone for a while, and then gradually lost 

Riess: You described a back yard in one of the houses that could 
become an ice rink. 

Schawlow: That was at A36 Sackville Street. It was hardly bigger than 
this room, actually. It was very small. But the winters, 
sometimesnot every year, some years it would be cold enough, 
you'd just flood it and you'd have ice. You couldn't skate 
very far because, as I say, it was small oh, maybe twenty feet 

Interestingly enough, the house is still there. I went 
back a couple of years ago and took some pictures. The only 
thing that's changed from the outside is that they have a 
veranda or porch all the way around two sides it's on a 
corner and instead of having a wooden railing, it now has a 
metal railing. That's about the only thing I could see that 
obviously was changed from the outside. 

'Arthur Schawlow had begun an autobiography that he loaned to the 
interviewer for background information. 

We had the ground floor. There was an elderly couple 
living upstairs, the Duffs. He, I gather, was a member of the 
MacDuff family from Scotland, sort of an aristocratic family. 
We heard a rumor that when he married his wife, that somehow or 
other they disowned him. Anyway, I don't know about that. He 
was a lawyer, worked for the city. They were pleasant people, 
but we didn't have much to do with them. 

Riess: Toronto, to the extent that I know about it, and it's mostly 
from literature, is a kind of immigrant city. 

Schawlow: Even more so now, yes. Well, at that time, yes. See, this was 
not long after World War I, and there was a lot of immigration 
from the British Isles, so a lot of English, Irish, Scotch-- 
"Scottish," as they prefer. In fact, somebody was telling me 
yesterday that he asked somebody if he was Scotch, and he said, 
"Either Scottish or a Scot. Scotch is something you drink." 

We did have some good friends, like the Anguses, that were 
real Scots, and I've always felt a liking for Scots since then. 
Both their children were deaf, Elma and her brother were pretty 
deaf, but Elma became quite expert at Highland dancing. We 
were invited once to watch her rehearse in a living room, oh, I 
don't know, maybe fifteen feet square, and there was a 
bagpiper. I've never heard any noise as loud as that! A 
bagpiper in a little room like that! 

[laughs] Was that before or after you had your tonsils out? 
Maybe it affected your hearing? 

That was probably after, I think. [laughs] I don't think that 
one evening, an hour or so of bagpipe, would have affected my 

Another incident you talk about in the autobiography was when 
you were rescued by a babysitter. Was this seriously a near 

Yes, she thinks so. [chuckles] I wasn't worried. I felt I 
was all right, but apparently I was getting in over my depth. 
It was in the lake, Lake Ontario, which is an enormous lake. 
It was a beach at a town called Scarborough. I don't know, I 
wasn't worried, but she came out and grabbed me, and maybe I 
would 've drowned otherwise. But I didn't feel that I was 
drowning. Helen is still around, I saw her a year or so ago. 

Riess: Helen was the babysitter. 

Schawlow: Yes, Helen Egan--and her brother, Vincent, and I used to play 



Riess : 


Religious and Cultural Milieu 

Riess: Where has this background left you with religion? 

Schawlow: Well, I'm a fairly orthodox Protestant. I've been in a lot of 
Protestant churches. I have to laugh--! don't know whether I 
put it in there [autobiography]: one time, Vincent Egan said, 
"You're a Protestant." And I said, "I'm not, I'm an American.' 
I'd never heard the term Protestant before. But as we moved 
around we were always in the United Church- -when we were in 
Toronto. And when I went to New York I went to the Riverside 
Church, which is affiliated with the Baptists but really is 
nondenominational . 

Then, after I got married, my wife got a job as organist 
and choir director of the Baptist Church in Morristown [New 
Jersey] . This Baptist church is not at all what you think of 
as Baptist; it's a very liberal, Northern Baptist church. The 
minister was very much interested in interracial friendships 
and inter faith and so on. So we went there. Then, when we 
came out to California, after a while Aurelia got a job at the 
Congregational Community Church in Ladera, which is on the 
outskirts of Palo Alto. 



After we had the third child the job was too much, so we 
started going to a Methodist church in Madison, New Jersey, 
while we were still in New Jersey. That was ok. But then we 
moved to California. We've been in Presbyterian and 
Congregational churches around Palo Alto. Recently my son and 
I both joined the Methodist Church in Paradise, California, and 
that's the only one I go to now. 

So, I don't know--I don't like to be pushed on what exactly 
I think about religion, because I think a lot of it I don't 
know. But I think the world is too wonderful to have just 
happened. And I think that orthodox Christianity is a good 
conduct for life, and I hope it's true. 

And I don't mean to push you at all. I guess maybe one of the 
ways that I would ask about how religious one is , is whether in 
a crisis you really pray to something. 

Yes, I do. I'm never surein fact, I say my prayers every 
night. I really don't know for sure if there's somebody 
listening, but it seems to help. Somehow, I feel that there's 
somebody else in charge. 

Riess: Well, yes, the alternative is the hardest. 

Schawlow: There is a booklet's see, it's called Cosmos, Bios, Theos . 
It was by [Henry] Margenau and [Roy Abraham] Varghese. 
Professor Margenau, who had retired from Yale University, wrote 
a number of people and sent them a questionnaire about 
religion. I answered, and 1 have a page or so in that which I 
can probably dig up for you. I think the copy is somewhere 
around here. We can look later. 

But I haven't gotten around like Charlie [Charles Townes] 
has, giving talks about religion. I remember once there was a 
wonderful minister filling in at this church in Ladera. He 
asked me if I would like to preach a sermon some Sunday, during 
the summer particularly, I think. I said, "Well, it reminds me 
of the sign at the barber shop. It says, 'We have an 
understanding with the bank: they don't cut hair and we don't 
cash checks. ' " 

Riess: [laughter] That's good. Actually, I would find that somewhat 
disconcerting. After all, a role thing is very important 
there, to maintain the ministerial role. 

You said you felt your father had a kind of mathematical 

Schawlow: Well, I mostly saw him on arithmetic. One of the horrible 

things about that job was that every week they had to prepare 
their accounts, and they had to list every single policy on a 
great big sheet of paper, I don't know, maybe two and a half 
feet square or something like that. And they were long 
columns, and you'd have to move the policies from one week to 
the other as they were paid up. Then they have to add up all 
these columns, and the differences had to equal the amount of 
money that they turned in as they moved from one week to the 
next- -it was marked as paid up. So he had to do a lot of 

When I was in high school I used to help on that sometimes, 
and I think I got pretty good at addition. He knew something 
about geometry, but we didn't discuss it very much. He could 
always beat me at chessespecially if we bet even one cent, he 
would beat me. But I didn't take chess very seriously. I got 
a book and studied it some, but I have never taken games very 

He would 've made a poor engineer, I think, because he had 
no feeling for mechanical things. My mother used to do any 
repairs that had to be done around the house often in a way 
that sort of shocked you really, because it was rough and 

ready: whatever was at hand, she'd string things together with 
it. I think she might 've made a better engineer. I think he 
could 've become a theoretical engineer or a scientist, and it's 
perhaps a pity that he didn't. 

Riess: What other kinds of things do you remember doing with him? 

Schawlow: Well, he was very busy, of course. We'd go for drives and 

occasionally walkshe would drive us out in the country. We 
did play chess some. And I don't really remember anything else 
very much. 

Riess: It sounds like he worked very hard. Maybe there was a sense 
of, "Your father is working. Don't disturb him." 

Schawlow: Well, he had to go out essentially every evening, because 
that's when people were home. He had to make these 
collections. He didn't have a lot of time. 

Riess: Did your house have books, music? What was the ambience? 

Schawlow: We did have a Victrola that somebody gave us at one time, a 
windup one, and we had a few records, I think, that had come 
with it. For a while somebody lent us a reed organ, and I 
tried to take piano lessons and practice on that, but that was 
hopeless, you can't play piano stuff on a reed organ. We even 
had a piano that somebody lent to us for a while, but I don't 
think we felt that we could afford to buy a piano. No, there 
wasn't a lot of music around the house. Oh, we had the radio, 
and of course, that was a wonderful thing, there was all kinds 
of music on the radio. 

I had asthma when I was a boy. We used to go to a farm in 
the country for some weeks in the summer, but then I started 
getting asthma very badly from an allergy to ragweed. They did 
tests, and they gave me shots for it. Eventually, I outgrew 
it. I think what happens isI've been told that the irritated 
linings of the bronchial passages don't go away, but they get 
bigger so there's room for the air to flow through. 

But because of this asthma, somebody suggested I should 
take singing lessons. And I did take singing lessons from a 
very good teacher. She never told me that I really couldn't 
sing. I had a good voice, but I couldn't carry a tune, really. 
I just have a poor tonal memory. 

I did sing for a while in an Anglican church boy's choir 
[laughs] that's another of my religious variations. It was a 
small church, not a big one. I think I had a nice boy's 
soprano voice. It used to bother me that things didn't sound 


right to me, but I couldn't tell what was wrong. She was very 
good. One of her sons had a somewhat successful career as a 
singer in the United States. The other one was an artist. She 
was Mrs. Louise Tandy Murch, and she lived to be almost a 
hundred. My sister sent me a newspaper clipping about her. 
But I lost touch with her when we moved out to the suburbs. I 
think the Depression was really beginning to bite, and my 
parents said I had to stop the singing lessons. Well, it 
didn't matter too much because I really wasn't much of a 

Riess: And did that really help the asthma? Was the idea that you 
learned a different kind of breathing? What was the point? 

Schawlow: I don't know. I guess that you exercise your lungs and so on, 
maybe build up lung capacity. 

At that time, under Mrs. Murch' s influence, I thought there 
was no music but classical. We didn't listen to an awful lot 
of anything, to tell you the truth, but there was a lot of 
light classical music on the radio in those days. I remember 
there was a program on Sundays by Ernest Seitz who played the 
piano, light classical stuff. He and Gene Lockhart, who later 
became a successful movie actor, wrote "The World Is Waiting 
for the Sunrise." 

Early Interest in Engineering and Science it 

Schawlow: There was a library branch within about a half a mile or so, 
and particularly in the summer we'd go over there and get as 
many books as they'd let us take out--I guess it was six or so 
at a timeread through them and bring them back and get some 
more. So I read a lot of books. 

Riess: What were you reading? 

Schawlow: I was interested in things concerned with engineering and 

Riess: We're talking about little Artie. Little Artie? 

Schawlow: I was never called Artie. My family called me Bud, and they 
still do. But yes, even then I had those interests. Once I 
started to use a Meccano set, I started to read Meccano 
magazine and that had stuff about building bridges and that 
sort of thing. I was interested in radio, although I didn't 
have any money to build anything much. I think I built a 
crystal set. And then we also read a lot of books, oh, of 


mythology- -The Iliad and The Odyssey, and some of the Norse 
legends, too. 

Riess: And adventures? 

Schawlow: Yes. There were some good books. There was a series of books 
about a Boy Scout named Roy Blakeley, I think. I don't know 
what the kids get now, I don't see any such things. These were 
good for, well, going on towards teenage. I read a lot of 
Jules Verne. 

One thing I didn't mention about the cultural background: 
at home we had the Book of Knowledge. It was a wonderful 
thing. It had summaries of a lot of famous stories, so I got 
some idea of what they were about. I spent a lot of time 
reading that. 

Riess: How is that different from an encyclopedia? 

Schawlow: It's not written as an encyclopedia. I don't remember how it's 
arranged. Actually, I found a copy in a used book collection 
and bought one, left it up in Paradise a couple of years ago, 
but I haven't looked into it. Well, it was almost more like a 
magazine, or collections of articles on various subjects and 
stories. There were some stories, as I say, some summaries of 
famous stories. 

Riess: Was it a series? 

Schawlow: Well, it came out all at one time, but it was a set of books. 

Riess: Did you have an encyclopedia? 

Schawlow: I don't think so, no. I don't think we had an encyclopedia. 

Riess: What do you think: if you had been given a chemistry set 
instead of a Meccano set, where would you be today? 

Schawlow: Oh, goodness. I did play a little bit with chemistry sets at 
one time or another, but they didn't really intrigue me so 

It was radio, really, that intrigued me, and I read a lot 
of books about radio even starting then. And there were people 
who had old radio magazines that I could get and read through 
some of them, I think even when I was on Sackville Street--! 
left at age eleven, but I'd finished grade school by then. 

Riess: Let's go back to the grade school years. You were skipping 
some grades in school. 

Schawlow: Yes, I was. Until I met Miss Bray. 

Riess: Were you head and shoulders above your classmates? Why did 
they push you on so? Now they tend not to do that kind of 

Schawlow: I don't know. I guess I could do anything that they put in 
front of me, and I had a good memory at that time, I could 
learn things fast. 

I don't really know. I guess I was a lot better than most 
of the others. One thing I do remember, and I think it was a 
very good thing, when I went to the Model School I was a couple 
of years younger than most of the others in the class, and it 
was a selected group, too. I felt that some things I could do 
better than them. Still, it kept me from getting a swelled 
head, thinking I was smarter than everyone else. 

I've known a number of scientists who apparently were the 
boy genius all their life, and they're really pretty arrogant. 
But I learned that there were other people that are pretty 
good, too. I'm not very competitive; in fact, I think I'm 
about the most uncompetitive person you ever saw. And I avoid 
competitionprobably one of the reason I don't like games: I 
don't like to lose and I don't like to see somebody else lose, 
either. So I never really worried too much about what others 
were doing, I just did what I was asked to dodidn't go much 
beyond it, either. 

Riess: I guess a lot of physicists and engineers have a love of radio 
as the beginning of their life story. 

Schawlow: It was so exciting, really. I remember when we got our first 
radio it must have been about 1925 or 1926, and it was 
battery-operatedall the kids on the block would come around 
to listen to "Santa Claus' Adventures on the way from the North 
Pole," sponsored by our local department store, Eaton's. Also, 
the newspapers had articles every week on how to build radio 
sets with circuit diagrams. There was a lot of excitement. 

Riess: You were offered the means to make this thing. 

Schawlow: It was wonderful. The radios were made out of standard parts, 
and you could put together almost anything that was known then 
out of standard parts. For a while, you could build things 
cheaper than you could buy them. But then eventually they got 
into mass production and it really wasn't possible to do it. 
Well, people moved to the short waves, whereas the broadcast 


band was pretty much standard factory items. People built 
their own short wave sets, and I did too a little bit. 

Riess: Can you remember struggling with the concept of radio waves, of 
how they were was transmitted? 

Schawlow: No, I can't remember struggling with it. 

Riess: You understood it right away? 

Schawlow: Either I understood it, or I didn't worry about it. [chuckle] 

Riess: I'd sort of like to know. 

Schawlow: I guess I understood something. [pauses] I may have gotten 

something out of that Book of Knowledge about it; they may well 
have had a section on radios and how they work. No, I don't 
remember ever worrying about it. But my knowledge was not very 

Riess: I'm interested in your general curiosity as a kid. For 

instance, when you're out taking a ride with your father in the 
car, and you see the telephone wires looping down the highway, 
does that make you start to think about--? 

Schawlow: It does more now than it did then. I remember, maybe twenty 
years or so ago, I was in England taking a ride on the train. 
It was an electric train, and I was thinking, "What a marvelous 
thing it is: this invisible electricity flows through here and 
moves this huge train." I guess I had a sense of wonder and 
interest all along the way, but I learned it in little bits and 

Riess: You're saying that it was the sheer pleasure of building things 
that was more appealing? 

Schawlow: I think understanding things was more appealing, but then 

building, too. I really wasn't very good at building because I 
was very clumsy. And I didn't really have a lot of money to 
spend on it, either. Building it and having something work, 
and produce some music out of the air--that was pretty 

Riess: Dealing with what you describe as your clumsiness wasyou 
obviously surmounted it. 

Schawlow: Well, I got people to do things for me. [laughs] 

Riess: Is that really true or is this just some kind of legend that 
you have of yourself? 


Schawlow: No, it's true. In fact, my students and technicians don't want 
me to touch the equipment some of the time. I learned some 
tricks to do things, finally. I realize the reason now why I 
don't like mice on computers is that you have to position the 
pointer, the cursor, exactly, and I find that hard to do. I 
really find it hard to get that thing placed exactly where it's 
supposed to go. I can do it, but it's not easy. 

I don't think I ever passed in art class; however, they let 
me through anyway. As I think I wrote down in that draft for a 
biography, when I got to high school I had to choose between 
either taking art and botany, or bookkeeping and typing. I 
knew I couldn't pass art, so I took bookkeeping and typing 
because I really am very clumsy. 

Riess: That is a surprising anecdote to me, because you were obviously 
smart, and I should think any school counselor would say you've 
got to take botany because that's the academic track. 

Schawlow: I don't think we had a school counselor then. I'm not sure 
they'd been invented. 

Riess: But it turned out to be a good thing to have taken typing. 

Schawlow: Yes, it was good. I was all right. I'm not a great typist; I 
can type fast, but not accurately. I think computers were 
invented for me because I can make my mistakes and fix them. 

Riess: I noted in your autobiography, when you were talking about 
using your hands, that a psychologist was consulted. Why? 

Schawlow: Did I say psychologist? It was some kind of a doctor. 

Riess: [referring to pages of the autobiography] "Someone, I think it 
was a psychologist, told my mother I would never make my living 
by my hands . " 

Schawlow: I see. Well, now I don't know. It might have been just a 

medical doctor, but I guess she had noticed I was clumsy. When 
I had this trouble with the teacher in the--I guess you'd call 
it fifth grade, but it was junior third, they number them 
junior and senior first, junior and senior second, and so on. 

Riess: Please go back and tell that story, because it won't be on our 
tape. After you'd skipped one grade and skipped another grade, 
you landed in the hands of 

Schawlow: this teacher [Miss Bray) , a woman who had liked my sister 
very much, but somehow didn't like me, and claimed I was 


stupid, and also claimed I liked throwing spitballs. I had to 
ask my mother, "What's a spitball?" I really didn't know. 

So my mother took me to a psychologist who gave me an I.Q. 
test. And I hate to give you a number for printing--! can tell 
youbut it came out as 152. As I say, I hate to put that down 
in writing because I.Q. tests are very unreliable--! mean, 
quantitatively: I might have gotten more one day, less another 
day. Anyway, that's when she arranged for me to go to the 
Normal Model School. I guess he suggested it, probably. 

But as I say, the teacher had said I was stupidothers 
hadn't thought so. 

Riess: Yes! 

Schawlow: I guess I can't be sure who it was who had suggested the 
Meccano set. 

Riess: You knew you wanted to be an engineer? Had you met an 
engineer? Did you know what an engineer really did? 

Schawlow: No. Well, I had read a lot of books about engineering, I mean 
about the achievements of engineers, and I knew about building 
bridges and highways, and all that sort of thing. But did I 
know about the day-to-day work where they have to sit at the 
drafting tables and draw complicated diagrams? No, I didn't 
know about that . 

I did meet one radio engineer, briefly, who was some friend 
of a friend. And this man had a hard time. He got a 
bachelor's degree in electrical engineering and couldn't get a 
job. During the Depression, for a while he was winding coils 
in a radio factory, strictly a technician's job. I don't know 
what became of him later, but I knew that wasn't what engineers 
were supposed to do. I thought they were supposed to invent 
and design equipment. 

Riess: This was a time of a great flowering of engineering, wasn't it? 

Schawlow: Well, there was a lot of engineering going on. Of course, 

engineering had really started in the mid-nineteenth century. 
I mean, I read about the people who designed the railroads, 
Isambard Kingdom Brunei, who built the Great Western Railway, 
and some wonderful bridges, and also the first steamship for 
running cable across the Atlantic. Much later, when we went to 
England in the 1970s, I went to Bristol and saw one of the 
bridges that he had built. I thought that was pretty wonderful 



Electrical engineering, of course, that really didn't begin 
with Faraday. I mean Faraday's invention of the dynamo was 
necessary, but it took a while before it really became an 
engineering thing, not science. But it waswell, electricity 
and Edison and so on, and electric light distribution things, 
those were before the twentieth century, I think. They were 
pretty much underway. 

Did you imagine yourself being a kind of master builder along 
these lines? 

Schawlow: I could imagine myself being a master builder, but I really 
couldn't have done it. 

Riess: Had you heard of physics? 

Schawlow: Not very much; I guess I'd heard of it, yes. I was interested 
in electricity, mechanics, and so on, so I guess I knew that 
that was the sort of thing that physics dealt with. I know not 
everybody had. I remember once, during the war-time years I 
think it was, 1 met the mother of one of my friends and I 
mentioned that I was studying physics. She didn't know what 
that was, thought it had something to do with medicine. 

High School. Vaughan Road Collegiate Institute 

Riess: I think we're at the point where you made the move to the other 

Schawlow: Yes. I went to high school there, yes. And I was, of course, 
the youngest one in my class, but I didn't have too much 
trouble with the coursework. I don't know, my sister seemed to 
think I just breezed through it, but I felt I was working. I 
always had a lot of things to occupy me: I was still interested 
in radio and beginning to build a shortwave set, a two-tube 
shortwave set, things like that. 

Riess: Did you always do that from magazines and kits, or did you have 
some mentor who helped you? 

Schawlow: Not kits. Mostly magazines. When I was about mid-way through 
high school I met a man named William James Crittle. He was a 
radio technician, really. He had been gassed in World War I 
and was living on his pension pretty much. He was a very 
enthusiastic radio amateur. I used to go over and talk with 
him after school quite often. And, as I say, he wasn't really 
working. I learned some things from him, but at other times I 


was shocked by his ignorance of fundamentals. I had mentioned 
something about the crest of a radio wave, and he thought that 
was up at the top of the atmosphere. Whereas the crest is the 
place where the electric field is the maximum of the 
electromagnetic wave. 

Then I tried to build a super heterodyne radio, and it 
didn't work, so he took it apart and rebuilt it for me. So I 
never really built a very big radio set; two tubes was as about 
as far as 1 succeeded. 



You took Latin, French, and German, 

Were you good in 



I don't know. I had no trouble, and I was always near the top 
of the class, but I never learned to speak any languageswell, 
they didn't really try to teach you to speak. I'm not like 
these kind of people who pick up another language every year, 
but I never had any trouble with it. I always could do very 
well with what we were asked to do. I tended to do that with 
my coursework; whatever I was asked to do, I did. But I didn't 
go beyond it much. 

Except in the things that you loved? The physics and 

Well, the physics and chemistry, I read a lot around them, but 
I didn't really try to go deeper into the particular things 
that we were being told to study. In the third year of high 
school we started to take a physics course, from a man named 
Harston who obviously didn't know very much. He was also the 
part-time physical training instructor. It was all right, but 
not very stimulating. The fourth year, I think we took 
chemistry. And then the fifth year, chemistry and physics. 

Those last three were from a man named Robinson, C.W.T. 
Robinson, who was known to everybody as "Speedy," because he 
had a rather slow way of talking- -although amazingly, he had 
been a fighter pilot in World War I. We had five years of high 
school, thirteen grades in Canada. I think they still do, but 
I really don't know why because the Americans, at least those 
that come to Stanford, are just as well-prepared as we ever 
were. But perhaps I couldn't have taken so many languages if 
it hadn't been for that. Anyway, in the last year he just told 
me to do all the problems in the book at my own pace. That was 
pretty good, so I learned everything that was in that textbook; 
but I didn't try to get another, more advanced textbook or 
anything like that. I sort of read the popular accounts of 
what was going on. 







In high school mathematics I was at the top of the class, 
could do very well. Got to universityit was much tougher. 
There were people there who really had mathematical talent--! 
had to struggle. And then when we got on toward the fourth 
year, the last year of college--! don't know, it's fortunate 
that we didn't finish the year, because the war was on and they 
put us to work teaching classes--! found that physics was 
getting very mathematical, and I didn't like it. 

I liked to visualize things, and I think that's one of my 
abilitiesalthough I haven't got a good eye. I always tell 
people that I think in terms of fuzzy pictures, but I'm pretty 
good at that. I sort of train myself to think, "What's the 
essence of this? What's this all about?" It got sort of 
discouraging as the physics became more a matter of equations 
and formulas . 

But then after I graduated I came across this wonderful 
book by Karl Darrow I think he called it An Introduction to 
Contemporary Physics [Van Nostrand, 1926]. Karl was a nephew 
of the famous lawyer Clarence Darrow, and for many years he was 
the secretary of the American Physical Society. Anyway, this 
book described the basic experiments on which modern physics 
was based, what they did and what they found, and that was the 
kind of physics I likednot writing out equations. 

That really didn't happen until the end of college? 

Yes. Well, it didn't really get that bad until then. I don't 
know, it seemed like physics, a lot of it was with concepts and 
learning facts about things, how things worked. But then they 
sort of get into the more formal mathematical treatment and I 
didn't like that. 

Physics wasn't sold to you as the underlying principles of 

Well, I guess it really wasn't sold to me. 
Sorry, I didn't really mean that. 

I don't know. Well, physics certainly seemed already by then 
to be the basic laws of the way things worked. But for 
instance, we didn't have transistors, or semiconductor devices, 
and so it wasn't really fully appreciated the way physics, 
solid state physics, would open up a whole world of devices and 
so on. It certainly was the way that structures, like bridges, 
had to be designed to withstand the stresses-- 


Some Beliefs, and Some Disbeliefs ## 

Riess: [looking at Cosmos, Bios. Theos] Why are people so fond of 

asking scientists for the answer? After all, they don't ask 
art historians for the answer. 

Schawlow: Well, the man who edited that book, Cosmos, Bios, Theos, was a 
physicist, and so perhaps that's why he thought of asking 

Riess: But you know it's more than that, too. 

Schawlow: Yes. Yes, I guess so. I think that you confront the universe 
and perhaps learn something about it that wasn't known. And 
there's, of course, a long history of complaints that science 
conflicts with religion. I don't think it should. But on the 
other hand, religion has very often tried to explain the things 
that we don't understand, and then science comes along and 
explains them, and they feel, "Oh, boy, God's been moved out of 
that part of the universe, too." 

You know, centuries ago everything seemed magic, we didn't 
understand anything much. But as we have science we do 
understand a lot more in a straightforward way. Still, there's 
so much we don't understand that I think there's an awful lot 
of room for religioncertainly a guide for ethics. As I think 
I said a while ago, the world is just so wonderful that I can't 
imagine it was just having come by pure chance. 

Riess: When you say that, "The world is so wonderful," what do you 
picture right away when you say "the world is wonderful"? 

Schawlow: I think the beauty of the trees and flowers and so on, and the 
fact that people can exist and have produced such marvelous 
artistic creations, in sculpture, painting, and music. Of 
course people ask, If God exists, why does he allow such 
terrible things to happen? And there certainly is a lot of 
evil in the world- -and a lot of good, too. In every family, 
usually, the parents provide love for the children, at least in 
most families, and that's a wonderful thing. 

Riess: What do you think about afterlife? 

Schawlow: I don't know what to think. As I've mentioned even to Charlie, 
I don't see any place in this universe for a heaven. We've 
explored it pretty thoroughly, so that if there is any, it has 
to be very different from anything that we can imagine here. 
It's not tucked just above the clouds, there, we're sure of 
that. On the other hand, if you think that the whole human 


being is encoded in a tiny bit of DNA, which is so small that 
you couldn't see it without a microscope, then perhaps the 
essence of a human being is somehow transmitted to a different 
sort of universe. 

You know, in some ways, I think that the soul, such as it 
is, is sort of the operating system of the human. It's more 
software than hardware, in the modern metaphor. Of course, 
that metaphor may be thoroughly dated in a little while. But 
you know, there were some people who, I guess, were religious 
skeptics. They said, "Well, let's weigh the body as the person 
dies and see if the soul is escaping." I think that doesn't 
make any sense. 

But unfortunately, as you get older it gets harder to feel 
confident that there's an afterlife, or that it's anything at 
all like life. Perhaps if I spent more time in church I would 
feel stronger. One of my daughters has gotten very 
passionately fundamentalist and would like me to become so, 
too, but I don't think it's in me. 

I would think it would 

Riess: Why does it change as you get older? 
work the other way. 

Schawlow: It's getting closer. 

My mother, too. She sort of lost her faith as she got 
older. I don't know, really. I guess I'm just honestly saying 
that I do not know, and I don't think that anybody can know. 
On the other hand, unless the story of the resurrection is a 
total lieand it seems to be well attestedthen there are 
some things that are beyond our ken. 

And I don't understand our daughter, this one I mentioned 
who feels that salvation comes from the sacrifice of Jesus. 
Well, it's an interesting biblical concept of sacrifice, which 
is not really a modern concept at all: I mean, why you have to 
sacrifice something to get a good end, I don't know. On the 
other hand, if you had to have Jesus die and then be 
resurrected, that certainly shows you something that you don't 
get out of the books. Maybe I'll eventually be able to accept 
the concept. 

One of the things that I got, a piece of software, is a 
Bible search program. I looked up the word "faith," and it 
hardly occurs at all in the Old Testament! 

As far as I understand the Old Testament--! 'm not a 
biblical scholar, but I've been in a lot of church services and 








I've heard a lot--I think that some of the Jewish people 
believed that there were other gods, but their god was the 
supreme one. I don't think that they really believed that the 
other ones didn't exist. I don't knowbut at least you could 
read it that way, I think. But there certainly are some 
strange things. The Bible, of course, is a wonderful guide to 

human behavior, what works and what doesn't work. 
a variety of things there. 

There ' s such 

In church a few weeks ago the minister was discussing the 
story of Abraham and Isaac, where he was ready to sacrifice his 
only son. That's a strange story. In the end, I gather God 
said to him, "Now I know I can trust you" or something like 

That's about faith, I guess. 
I guess so. 

I'm not the person to give you a good religious education, 
because I just sort of learned. I think I have one principle 
in doing science: start off believing everything. Because 
otherwise, I've seen people who are skeptical about everything 
new, and they don't believe anything, and they miss the boat. 
But on the other hand, you can question anything. You don't 
question everything, because then you're just a crackpot, but 
you can question anything. And so, I guess I tend to have that 
attitude toward religion. I don't know. 

How do you figure out which thing to question? 
question in science. 

That's the 

Yes. Partly instinct and partly a matter of seeing what 
doesn't make sense. If things don't fit together, then you try 
and see what's missing. 

I spent some time with a book that's been much discussed and 
reviewed, called The End of Science [by John Horgan, Addison- 
Wesley Press, 1996]. 

Ooh! What nonsenseabsolute nonsense. I haven't read the 
book, but I read the reviews of it and I think it is nonsense. 
First of all, I gather it acts as if particle physics is all 
that there is, and 

It does. And cosmology at least in terms of your fields. 
Yes, and those are not my fields at all. 



I think there are some wonderful questions in atomic 
physics and condensed matter physics. I'm fascinated now by 
the questions of nonlocality, where in quantum mechanics things 
don't seem to be anywhere until you measure them. So you get 
correlations between distant places more quickly if they start 
out correlated, and say, two particles move apart in opposite 
direction- -when you measure them, the measurement on one 
affects what you can measure on the other one. It's considered 
to be instantaneous, but there isn't really proof of that. In 
fact, I'm trying to look to see what has been measured and what 
could be measured. So I think the fundamental questions of 
quantum mechanics and its interpretation are far from finished. 

The author is provocative. He does quote [Hans] Bethe as 
saying that important discoveries will continue in solid state 
physics, but that there are no exciting, big discoveries left. 

Schawlow: Depends what excites you. 

I've seen particle physics develop kind of as a spectator; 
it really didn't exist when I was a student. All we had was 
the proton and the neutron and the electron. Now they have 
this whole zoo of particles; they have more particles to 
explain things than the ancient astronomers had epicycles. 

Riess: Physics can be a kind of playground for popularizing writers, 
and for religious writers too. 

Schawlow: Anybody's free to speculate anything they want, but 

fortunately, nature has provided us with a great analog 
computer, experiment, which will tell us how to solve our 

I have read several semi-popular books on the 
interpretation of quantum mechanics lately. The religious 
speculations, I just don't see how they can tell me anything 
that I don't know. But I may be wrong, there. 

Riess: Okay, well, let's go back to 

Schawlow: Actually, let me say one more thing about religion. There are 
enormously different cults and religious sects, and I think 
it's not unreasonable, because I think God--if he's as 
wonderful as we believe- -is also very complex, and that 
different people have to see him differently. Of course, like 
the blind man and the elephant story. But you can't expect a 
peasant and a philosopher to have the same picture of God. I 
think God is big enough to cover them all, even for science 
writersthey can have their picture of God. 


Riess: And even if they're trying to prove that he's not there, that 
means that they're concerned about him. 

Schawlow: I don't think they'll ever prove that, any more than you can 
prove existence. I think we just have to learn to live with 
uncertainty, and you sort of place your bets on what you think 
is most reasonable, which is where I come down. Maybe I'm 
wrongcertainly the Bible complains about people of little 

Riess: Is the Bible that is in your computer program the King James 

Schawlow: Yes. You can get other versions, but I have the King James 

Riess: At least you get good writing. 

Schawlow: Marvelous. Incredibly beautiful writing. 

Entering College. University of Toronto 

Riess: To the extent that I know you through your autobiography, I 
think I've let you leap too far forward. 

We were getting from high school into college, and the 
decisions that were involved there, and the choice of subjects 
that you had. You graduated young from high school. 

Schawlow: Yes. I was just sixteen. 

Riess: What were the possibilities, in terms of higher education, in 

Schawlow: Well, there was one university, and as I say, because of money 
we couldn't even think of going anywhere else. In fact, if we 
could get into the university, that was going to strain all our 

If I hadn't been able to get into the university I would 
probably have tried to become some kind of a technician, a 
radio technician or something like that. I don't know- -there 
are schools that teach that, or you can learn it by experience. 
But, as I say, one didn't think of going to places like MIT. 
Either you got into the university or you didn't. 





I think I wanted to get into the university, and probably 
thought I would end up teaching high school. It was sort of 
the thing that I could imagine. I don't think anybody I knew, 
except doctors or dentists or teachers, had ever gone to 
college. People who lived around us hadn't. And so I really 
didn't have much of an idea what it was like. 

They have these big formal exams at the end of the last 
year in high school, which are given by the provincial 
department of education. They occupy several weeks in June. I 
thought, "Well, maybe I'm not good enough to get a 
scholarship," because there are all these schools where they 
have Ph.D.s for teachers, and so on, like Harbord and 
University of Toronto Schools, "but I'll see what I can do." 
Vaughan Road Collegiate was just ten years old, and nobody from 
there had ever won a science scholarship. 

It was 1937 and that was the year of the coronation of King 
George VI, and there was a possibility that I could have gone 
with the Boy Scout group to that coronation, but my parents 
wisely decided that I should stay and take the exams. So I 
did. When the results were announced in Septemberthey 
appeared in the newspapers, that's where you learned about 
them--I found that I'd gotten a scholarship for mathematics and 
physics. I knew I wouldn't get one for engineering because 
there were no scholarships for engineering at that time. 

The University of Toronto was not free to the populace? 

It was $125 a year, which doesn't seem like much money; even if 
you give it a factor of twenty for inflation, it would still be 
only $2500, which is not very much. But these were Depression 
days, and my father had two children. I think even with the 
scholarships it was a stretch, and he had to borrow money, 
though he didn't talk about that. So, $125 a year certainly 
doesn't seem like much. Before I graduated it went up to $175, 
but the scholarship covered that. And now I'm sure they're up 
in the thousands, though not like Stanford or Harvard. 

You said something, back there, about not having any Ph.D.s to 
teach you. But you went to the top high school in Toronto, 
didn't you? 

No, no, no. It was just the one that was near us. It was a 
good high school on the whole, but not a great high school. It 
was the Vaughan Road Collegiate Institute- -the "collegiate 
institute" meant that the heads of each department had to be 
qualified as specialists in a subject, like in French or 
English or whatever, so they had certain standards. I really 
had wanted to go to the University of Toronto school which was 
affiliated with the university. And that's where a lot of 


people from Model School went, but again, my parents felt they 
couldn't afford it, so I went to Vaughan Road. They covered 
the material that was described in the course, in the 
textbooks, but they didn't go beyond that; whereas, I think 
some of these other schools did give more advanced preparation. 
However, the exams were based on what was in the course, and I 
knew that thoroughly. 

Riess: About the decision of which part of the University of Toronto 
to attend--! don't understand how the University of Toronto 
works . 

Schawlow: They had what they called honor courses. It was specialized 
right from the beginning. I think my scholarship was for 
mathematics and physics, as I'd gotten high grades in that. I 
don't remember whether I had to specify that before then, maybe 
I did. I remember I applied to Victoria College, which 
happened to be affiliated with the United Church of Canada, but 
I didn't know that. I asked some teachers and they suggested 
Victoria College. You had to choose one. 

Riess: This is like the British system of a university having 
colleges . 

Schawlow: Yes. Colleges had dormitories and residences, and they had 
some college life in which I didn't really share because I 
lived at home and commuted by streetcar. In fact, I only took 
one course each year, I think, at the college. You had to take 
some sort of cultural subject that you would take in your 
college. But the main course was mathematics and physics; 
except for this one cultural subject, that's all you studied- 
mathematics, physics, and chemistry. And then after the second 
year, I think, it branched into physics and chemistry, or 
astronomy, or an actuarial science. Mathematics had an 
actuarial science specialty, and many of the top actuaries in 
the continent's big life insurance companies had graduated from 
there. We took courses in actuarial science the first and 
second year. 

Riess: Was that in some way like statistics? 

Schawlow: Well, yes, it's calculating probabilities. It's taking the 

life tables, for instance, life expectancies, and calculating 
how much something is worth based on life expectancy. 

Riess: Did this have any general application that you can think of? 

Schawlow: No, I don't think so. It was kind of fascinating because it 
was a lot of talking about what did you really mean here and 


formulating the equations that I found attractive, but I felt I 
never really quite got the hang of it to do it easily. 

Riess: Did talk to your father about it? It was sort of in his line. 

Schawlow: Well, not really. This is how the insurance companies would 
set their rates, you know, by taking the probabilities that a 
person would live so long. It's a strange subject. 

I took a terrible chemistry course--! may have mentioned 
that. This old Englishman named Kenrick taught it. He was the 
head of the chemistry department, but he hadn't learned 
anything since 1900, I think. He didn't believe in atoms. He 
only believed in chemicals, and he talked about a fictive 
constituent called "hydrogenion"--all in one word, instead of 
talking about hydrogen ions. Really, what chemistry I learned 
in high school is about all I learned. 

Riess: You said you had good memories of the physics labs. 

Schawlow: I enjoyed those. We had a good physics teacher for our first 

year. He was also about the same age as Kenrick. He graduated 
from Cambridge around 1905, and he'd written a number of 
textbooks, but had not done a lot of original research. But he 
worked hard at preparing problems every week and writing up 
solutions to these problems for us. He also supervised the 
lab, with some assistance. He was a very good lecturer--f airly 
dramatic style and a lot of fun. 

We had a wonderful calculus teacher, Samuel Beatty, who 
later was dean of the faculty of arts and later chancellor of 
the university. He made things very clear and interesting. 
Some of the othersmost of the other mathematics professors 
that I encountered were not so good as teachers, but then, 
perhaps it was because my ability was lacking. But I got 
through all right: in the first year, I was third in the 
mathematics and physics course out of about fifty students, 
something like that; in second year and third year, I was 
first. By third year, of course, we'd split off into physics, 
but I was top of the class before they split off. 

I felt I had to work awfully hard. 
Riess: You said you're not competitive. I don't understand. 

Schawlow: I wasn't. But I was scared that I'd lose my scholarship if I 

didn't get first class honors. And I would have. That was all 
I really was worried about. Now, looking back, okay, I can be 
pleased that I was at the top of the class, but the main thing 


was that I kept my scholarship. No, I didn't feel I was trying 
to beat out somebody particularly. 

Riess: Was there an opportunity to have some individual time with any 
of these people you respected? 

Schawlow: No, not really. We could go 'round and ask them a question if 
we needed to. 

Riess: Were you learning a lot out of books? 

Schawlow: Yes. I guess I was still reading some books about technology 
and science, sort of popular books about it. But my feeling 
around the courses at the university was that in high school, I 
felt I could learn everything that was taught, but in college, 
I knew I couldn't, so I just had to try and decide which was 
most important, and try and make sure I learned that well. It 
was really quite difficult. I felt I had to work pretty hard. 

Physics in the Prewar and War Years 

Riess: Charles Townes describes--! love the picture, and maybe I've 
elaborated on itsitting on a rock by a stream reading about 
special relativity. 1 

Schawlow: [laughs] I heard that he took a physics textbook with him to 
the circus once. That's what his sister told me. 




When were you introduced to special relativity? 
remember struggling with it? 

Do you 

I think we had a course on it. Yes, we must have had that, 
probably around the third or fourth year. I found it sort of 
interesting, but not thrilling. I don't know. I guess I could 
manipulate the equations as I needed it. I've never had the 
occasion to use it since then, and I'm not really fluent with 

When you say that, I guess I almost can't believe it because I 
think of science as a pyramid. 

'Charles Hard Townes, A Life in Physics: Bell Telephone Laboratories 
and World War II; Columbia University and the Laser; MIT and Government 
Service; California and Research In Astrophysics, Regional Oral History 
Office of The Bancroft Library, UC Berkeley, 1994. 


Schawlow: Well, it's a number of pyramids, I think. Relativity does come 
into atomic physics, but sort of in predigested form. I mean, 
there are people who have applied relativity to the motion of 
electrons and atoms. They obtain certain results such as the 
atomic spin-orbit coupling depends on relativity. But I 
haven't designed space ships or accelerated particles to 
relativistic speeds, so I just really haven't had much use for 
it. Thermodynamics is the same way. We took a course in 
thermodynamics, but I've never used it. It's a fact that 
actually, the old Tower of Babel is there; there are a lot of 
different branches of physics, and unfortunately, people who 
write books like The End of Science don't understand what we're 
doing, and vice versa. 

Riess: You mean by selecting particle physics as the essence of 
physics . 

Schawlow: Yes. I see how it happened all right. Atomic physics was the 
way to go in the twenties and it opened the door to quantum 
mechanics and that, of course, led to a lot of other things. 
But then you started looking at the fine details of the atom, 
like the nucleus, and that led you into nuclear physics. Then 
they started to get accelerators and so then they 

Schawlow: --started getting new particles, and the whole field of 

particle physics began. So they felt that they were leading to 
an essential simplicity. 

I haven't followed it closely because it just doesn't seem 
that they would have anything to offer me. Culturally, it's 
kind of interesting, but it deals with things in a very 
artificial sort of way, at very high energies, and you need 
huge machines to create them, and they only last for a 
trillionth of a second or something like that. What they do is 
they sort of follow spectroscopy and order things in patterns 
that are, really, in essence, based on atomic physicsalthough 
they've had to make some modifications which are fairly 

Riess: You say they follow spectroscopy? 

Schawlow: Yes, they do, in sorting out thingsangular momentum, 
selection rules, so onthey follow the ideas of atomic 
spectroscopy. Of course, it's different because these things 
are also strongly interacting. But it seems to be a field in 
itself that doesn't lead anywhere else as far as I can see. 


Riess: And yet, you think it's overly identified as the calling for 

Schawlow: Yes. I do. I think there are people who think that we know 
the laws of quantum mechanics and everything's understood in 
principle in the atomic everyday realm. Well, it may be 
understood in principle, but it's certainly not understood in 
many respects. 

Riess: The Tower of Babel image is the other extreme, sounds totally 
out of control and zipping off in all directions. 

Schawlow: I think so. This supercollider they wanted to build- -some 

physicists, like Phil Anderson, actually came out against it. 
He's a solid state theorist. I didn't do anything, one way or 
the other, but I think there were a lot of physicists who felt 
that's just not the kind of physics we know. 

I understand what this man [Horgan] is talking about, his 
book. The theories that they have now, there are a lot of wild 
theories: the theories of everything- -they call these string 
theorythat seem to require experimental facilities far beyond 
anything that we can ever hope to build, and that's certainly a 
dead end. I heard a talk that said that physics may be 
becoming like the cathedrals of the Middle Ages, which took 
centuries to build, and you can't do these problems in one 

Riess: One thing was interesting to me: he said science has existed as 
an activity for only a few hundred years, and yet people think 
of it as being a permanent feature of existence. But, in fact, 
it may not be. 

Schawlow: It may not be. Of course, even existence may not be permanent. 
There 're so many ways that people can destroy our world, it's 
really very upsetting. With missiles and atomic bombs, I can't 
think but sooner or later there'll be an accident, or a 
terrorist or a rogue nation will set off some of these things, 
and we may think it's another big countryit ' s horrible. When 
the United States and the Soviet Union were confronting each 
other, I could imagine that if Libya had gotten hold of an 
atomic bomb and set it off, we might think it was the Russians. 

Riess: Okay, I waylaid you by talking about special relativity. But 
were you beginning to zero in on what you wanted to do in 

Schawlow: No. All I would really study was radio. I did a lot of 

reading about radio, radio technology reallynot really deep 
science. No, what I wanted to dowell, like everybody else I 






thought atomic and 
After I came back, 
would really have 
run down by then; 
of the departments 
balance the budget 
up their research 
but they never got 

nuclear physics were the exciting things. 

after the war, nuclear physics was what I 
liked to have done. But Toronto was pretty 
they had suffered during the Depression. All 

were asked to give up something to help 

and the head of the physics department gave 
funds. It was supposed to be for one year, 

it back. 

So there was very little money to do anything. They didn't 
have an accelerator. And the system of government support of 
science hadn't been developed yet in Canada. You had to make 
do with what was available. Well, the nearest thing to nuclear 
physics was studying the properties of atomic nuclei by 
details, hyperfine structures it's called, in the spectra of 
atoms. There was a pretty good man in that field, Malcolm 
Crawford. So that's what I did. It isn't what I would 've most 
preferred, but I sort of have always taken advantage of the 
opportunities that present themselves. I haven't been a good 
planner, I just see what's available. 

Please go back and talk about the war period, 
chance that you would have been drafted? 

Was there any 

Yes, I could 've been drafted by two countries. I had to 
register in both Canada and the United States, because I was 
still an American citizen but residing in Canada. But the 
Canadians felt I wasn't a healthy enough specimen. 

You still had the asthma? 

Well, I had a stomach upset at that time. Strangely enough, 
the doctor who examined me at the draft place was the same one 
who had been treating it. Anyway, they turned me down. 

Was that upsetting? 

That I was turned down? No, I didn't want to go. 

What was your attitude? Was that a war you wanted to fight? 

I'm not a fighter. I felt it was a just war, all right, and it 
would be horrible if Hitler won it, but I didn't see myself 
being a fighter. I sort of was willing to be on the sidelines 
as long as I was doing something that was helpful. What I was 
doing was needed and required my knowledge. Later, the 
Americans wanted to draft me, but by that time, I was working 
for this Research Enterprises Limited radar factory. They had 
a representative in Washington who somehow got that stopped. 

Riess: Were you political during college? 

Schawlow: No. I'm just amazed thatwell, Canada had a liberal 

government, and had had one for quite a few years. I guess I 
felt that was sort of a good government. The word "liberal" 
wasn't considered as obnoxious as the Republicans seem to think 
it is nowadays. Well, I couldn't vote. I know we had one 
student who was a committed communist, and I could not 
understand that. We'd already seen in our newspapers articles 
about the show trials and concentration camps in Russiathis 
was no secret. I just couldn't understand how anybody could be 
a communist. But I wasn't active at all. I didn't have any 
time to do anything but study and play with radio a bit. 

Radio. Scouting, and Jazz Music 





And how about your summers? 

Did you support yourself with 

No, jobs were very scarce. The only time that I found a job 
was when a fellow student got me working for a couple of weeks 
in a factory that was making Christmas cards by silk screen 
printing. And I was helping there, most of the time cleaning 
Christmas cards: if they got a blob of paint you'd take a sharp 
knife and scrape it off. It paid twenty cents an hour. 

However in one year, I believe between the third and fourth 
year, I was allowed to serve as a volunteer in the radio lab at 
the physics department. 

That was during the year or in the summer? 

In the summer. 

It was a radio station? 

No. It was mostly a teaching lab. I don't remember that we 
really did very much, but I could learn to use some of the test 

You mentioned the Boy Scouts, 
your life? 

Was that an important part of 

Yes, it was fairly important for a while. I'm not really an 
outdoor person: I went camping one year, didn't like it much, 
but survived it. They were nice kids in Boy Scouts. We got 
along. One in particular, Bill Michael, became a close friend. 


I wanted to be a radio amateur, you know, but I couldn't 
qualify because you had to be a British subject to get a 
license. So I couldn't get a license; though I passed the 
test, I found I couldn't get it. But he had got an amateur 
radio station and I used to go down there sometime and help him 

Riess: What could he do with that? 

Schawlow: Well, it was Morse code. He would transmit and talk to other 
stations, other amateurs. Nothing terribly serious. But I 
thought it was very exciting to hear somebody from across the 
world or across the country. 

Yes, shortwave radio was exciting. I mentioned that I 
built this two-tube radio set when I was in high school. I 
used to come home at noon, because it was only a few hundred 
yards away- -some times the periods were staggered so I'd have a 
long lunch hourand I would tune up the radio and listen, and 
you'd get places from all over the world coming in. Quite 
amazing on amateur bands. I think one day I got ten different 
countries. That was exciting. 

Riess: Tell me what a two-tube radio is. 

Schawlow: A so-called regenerative receiver which is on the verge of 

oscillating, one tube, they can be quite sensitive, and so you 
adjust them so they're not quite oscillating. The second tube 
was just an audio amplifier to make the sound louder. 

I learned, although I'm clumsy, how to tune that thing 
finely. By putting my thumb and first finger on the knob and 
sort of balancing one against the otheryou push a little bit 
--I could adjust it quite finely, which I had to do to get 
anything to work. 

Riess: Did that make you want to make a better whatever-it-was? 

Schawlow: Yes, it would 've been nice to do that, and I did try to build 
this super heterodyne. As I say, I didn't get it working. 
This was about a five tube radio, I think, something like that. 
And I made some mistakes in the connections. I would 've liked 
to have a transmitter, too, an amateur radio station, and talk 
to people around the world, but that wasn't to be. 

The Boy Scouts--! got a lot of these proficiency badges I 
think they called them. I became a King's Scout, which is the 
highest rank, and got the gold cord, which you get if you have 
twenty-one badges or something like thatwhich is way beyond 
what anybody else in the troop was doing. But it was easy for 






me to learn a subject and qualify for a badge. I got some 
weird things, even bookbinderalthough my bookbinding was sort 
of barely passing. 

But what about the Eagle Scout rank? 

Didn't have that. King's Scout in Canada is about equivalent 
to the Eagle Scout in the United States, I think. That was the 
highest rank there. 

And when were you introduced to jazz? 

Was it in your college 

Yes. During my college years I had that radio, that super 
heterodyne, and I used to listen to it, and about the only 
thing that I found that I enjoyed was the swing music. There 
were a few other people I knew that knew a little bit more than 
I did about it. And there was a program, an afternoon swing 
session, that played some real jazz. 

Where was it broadcast from? 

It was from Hamilton, I think, which is about forty miles away 
from Toronto. Toronto, of course, didn't have very many black 
people. There wasn't a black district. It had tight liquor 
laws, so there weren't a lot of nightclubs. There were a few 
ballrooms where visiting bands would play, but I didn't go to 
those until later. 

But I started listening to the radio, and liked some of the 
swing bands that I heard. So I went to the music library to 
see if I could learn something about swing music, and there 
weren't any books on swing. But there were a couple of books 
on jazz, and I read those. And books came out around that 
time. So then I started to explore, look for people like Louis 
Armstrong and Bix Beiderbecke, trying to find their records. 
There were a few of them. 

Did you start buying them then? 

I started buying records in August, 1939. 

How do you remember August? 

[laughs] I can almost give you the date. One friend I'd met 
through the Meccano club had a place out in the country, near 
Toronto. I went out there for a night or so to observe the 
meteor shower, the Perseid meteor shower, which is just about 
the middle of August, and on the way back I had to change buses 
at the corner of Bay and Bloor, and there was the Promenade 


Music Center, and I went in and bought a copy of Artie Shaw's 
"Back Bay Shuffle," which is still a great record. 

It was interesting that the records on the popular jazz 
labels like Bluebird and Decca were thirty-five cents. And 
then the war started just a few weeks later. This was in 1939. 
Canada got into it the beginning of September, 1939. The price 
immediately went up to fifty cents. Of course, they were right 
to do that because shellac came mostly from India, and shipping 
was very difficult. So they knew there was going to be a 
shortage of materials. 

Mostly I bought records from the juke box stores. These 
companies, any new records that came out they put them on the 
juke boxes, and if they weren't getting a lot of plays they'd 
put them out and sell them. I think they were fifteen cents at 
first, later maybe a quarter. And you'd have to sift through 
whole piles of records, whole tables covered with piles of 
records, and learn to read upsidedown and sideways that way. 

Riess: Were they out of their jackets? 

Schawlow: They had just paper jackets where you could read the label. 

They didn't have fancy covers like LPs do. So I bought quite a 
few records that way over the next few years. 

Riess: And you had a record player that was your parents? 

Schawlow: Actually, at first I borrowed a windup record player from a 

fellow during the winterno, my parents didn't have onethen 
my father bought me one. Someone, I think one of his 
customers, had this thing for five dollars. It was just the 
turntable and pickup head, which by modern standards was 
enormously heavy. It was amusing: when it was a synchronous 
motor you'd start by spinning it, and you could start it 
backward to play things backward. I connected that to my 
radio, you see, it played through it, so I played these in my 

Riess: Did you have to invent something to connect it to the radio? 
Or could you just go and buy a gizmo? 

Schawlow: I think it took a little circuitry. I don't remember, really. 
It wasn't a big problem. I knew enough about how the radio 
worked to know where to connect it. 

Riess: Well, that's a great memory, isn't it? 


Schawlow: It was fun, yes. My sister was interested in jazz, too, so we 
shared records, she would buy some. Over the years we 
accumulated a number of records . I remember once one of my 
college classmates came over to my house and we played all the 
records I had. That was the last time I ever played all the 
records I had because I had too many to play. 

Riess: How much music was on a side? How much time? 

Schawlow: Three minutes, typically. Actually, I think there's a lot to 
be said for that. It imposes some discipline on the musicians 
--that was what a 78 rpm, ten-inch record would do. I think 
since LPs came along a lot of the more modern musicians get 
awfully long-winded and I think they ramble on for half an hour 
or so, whereas the great musicians of the swing and jazz era 
could say it all in a chorus or so. 

Riess: Do you have now, on CDs, rerecordings of these collections? 

Schawlow: I haven't everything, but I have a lot of them, yes. And I 
will probably build up more of those, too. Not everything I 
bought was good. In those days at least when you got one 
record that was a big event, and you'd play it over and over, 
really get to know it. You could even sort of pick out a 
particular passage because they [the grooves] were pretty 
spread out; you could put the needle down about the right 
place. Now, I really feel bad, I buy a CD, there's an hour's 
time on it, and I never really get to know it as well as I knew 
some of those old ones. 

Riess: It's the first thing you've described that would really take up 
the kind of time that you had been giving to your studies. 

Schawlow: Of course, not being a musician, I like to play music in the 
background while I'm working. 

Riess: Oh. But you couldn't do that with three-minute music. 

Schawlow: Yes, that's right. Couldn't do it very well--yes, changing the 
record. But the radio, when there was some jazz on, I didn't 
have to concentrate on it. 

Riess: And you did play an instrument also, didn't you? 

Schawlow: Well, during the war when my studies were interrupted, I 
decided I would try to learn to play clarinet. I really 
admired people like Artie Shaw, Benny Goodman, and Irving 


I don't know that last name--Fazola? 


Schawlow: Yes. He played, at that time, with the Bob Crosby Band. And 
one of the things that I'm very pleased with now is that 
there's a company in England that's gradually reissuing all of 
Bob Crosby's records. Very graduallyone comes out about 
every six months or so per year. But I've got a lot of those. 
And Fazola's just as wonderful as I remembered. He had the 
most beautiful tone of any clarinetist, jazz or classicalI'll 
play you a sample if you like. 

Anyway, I admired them. So I went to this teacher who 
offered to lend me a clarinet, to try it out. Well, I tried 
it, I thought it'd be nice, and I managed to buy one. 
Instruments were scarce then, and I bought a clarinet that was 
probably a mistake. It was a metal clarinet, but it was made 
by the Selmer Company, which is a very good company. It was a 
so-called full Boehm, which had extra keys so that a real 
musician could play A clarinet parts on it as well as the B- 
flat part. It made it somewhat easier. 

I enjoyed trying to play it, but it became apparent that I 
wasn't going to be a great musician. However, I got far along 
enough that I could play with a few other amateurs --we had a 
little jazz band. 

Riess: Where did you find them? 

Schawlow: It's hard to remember just exactly what came first. There were 
a group of people that used to get together to play jazz 
records. They'd come around to various houses. Then Clyde 
Clarke had a radio program. In fact, I still see Clyde every 
time I go to Toronto. He has a colossal collection. He's 
never thrown away anything. His wife died, and his children 
are grown, so he has the whole house to himself --full of 78s, 
LPs, 45 rpms, everything. Anyway, he had this radio program, 
and I think it was through that that I may have met some of the 
other people. They put on some of these record sessions in 
public. I remember carrying my amplifier and stuff down to a 
hall for some of them. 

Riess: So this doesn't have anything particularly to do with the 

Schawlow: None at all. I never took a music course at the university. 
Riess: No, but I mean that music wasn't centered at the university. 

Schawlow: No, I don't think jazz would have been considered something 

appropriate for the university. Although in this little Delta 
Jazz Band that I was involved with, we had a banjo player who 
was by far the best the musician in the band. He was an 




assistant professor of English at that time, named Priestley, 
F.E.L. Priestley. And his wife called him "Felp." [laughter] 

So what was it? The Delta--? 

Delta Jazz Band. 1 They were a pretty rough group. We tried to 
play New Orleans style, New Orleans revival. By that time 
records had appeared of some of the old New Orleans musicians 
who had never recorded before. Oh, it was wonderful stuff. We 
really enjoyed it. A number of us wanted to play like that. 
It had a beautiful swing. Always had two clarinets when I 
played with them, and I was the second one. We made a few 
recordings, but I lost them. Not commercial recording, just 
acetates, you know. 

We actually made a recording earlier when we were called 
the Southern Stompers. Slightly different. We admired--by 
that time the books Jazzman and Jazz Record Book 2 had come out, 
and they greatly influenced my interest. I tried to get a lot 
of the records that were mentioned in them, and build up my 

The way the Delta Jazz Band came to an end was thatwell, 
we weren't really very active, but when I got my Ph.D. I had a 
post-doctoral fellowship to go and work with Charlie Townes at 
Columbia. My sister was very proud, and she knew one of the 
university's publicity people and told him they ought to get 
that in the papers. He said, "Well, I don't know." But he 
called me up, and I told him--I could see he wasn't very 
interested in it--I told him that, "Well, fellowships are 
breaking up our Delta Jazz Band, because our banjo player is 
going to England on a Nuf field Fellowship and I'm going to 
Columbia." Boy, they really ate that up! It appeared in the 
national news of the Canadian Broadcasting Company. 

They liked that twist. 

Yes. I had a record of the Delta Jazz Band. I can't find it. 
Vanished. But I know somebody in Toronto, I think, who may 
have a copy of it. I'll have to pry it out of him. 

'For more on Toronto jazz see Toronto Jazz, A Survey of Live 
Appearances and Radio Broadcasts of Dixieland Jazz Experienced in Toronto 
During the Period 1948-1950, by Jack Litchfield, Harmony Printing Co., 

2 Jazz Record Book, by Charles Edward Smith, with Frederick Ramsey, 
jr., Charles Payne Rogers and William Russell. New York, Smith & Durrell, 




When tapes became popular, did you turn all of your records 
into tapes? 

No, not until much later. Actually I built a tape recorder 
with the help of a machinist from the universityvery early, 
about 1948 or so. It was a reel-to-reel recorder, of course. 
In fact, it didn't even have a capstan drive; one reel pulled 
the tape off the other one. Actually, I've still got some of 
those tapes. If I ever get time, I'm going to sort through 
them and see if there's anything worth listening to on them. 

No, I kept buying records. Tapes--! don't like reel-to- 
reel. In fact, I don't even like tapes at all because you 
can't find anything on them. I much prefer discs from that 
point of view. Except they're [tapes] good for getting a lot 
of stuff. After the LP came out I started buying LPs in 1950. 
Well, 78 rpm records seemed such a nuisance after a while. 
They took up a lot of space, and to keep changing them was 
really a nuisance. So eventually, I think somewhere around 
1980, I worked for several years and taped all the 78s. Then 
gave them to Stanford University's Archive of Recorded Sound. 

[Schawlow plays a minute of Bob Crosby band, featuring Irving Fazola] 

Seeing the Possibilities in a Career in Physics 
[Interview 2: August 21, 1996] ## 

Riess: I want to ask you about the facilities of the University of 
Toronto. Would you use the library at Victoria College? 

Schawlow: No, I wouldn't use the library at Victoria College. It was 
quite a long way away from the physics department where we 
spent most of our time. The physics department had its own 
library. And for general things the university library was not 
far away from the physics department. I don't think I ever 
used the Victoria College library. 

They're having a hard time with the colleges, Victoria and 
the others. They're losing their function. They were modeled 
on the English colleges where there's a lot of tutoring going 
on. I don't think they ever did that, but they did require you 
to take one cultural course at least, and they taught most of 
the cultural courses in the college. I mean, they had an 
English department, and Greek and Roman history, and I guess 
other history, too. But gradually, the university has taken 
over those functions. Now they don't quite know what their 


function really is, except that they do provide a dormitory for 
those who live there and they provide some social life which I 
didn't participate in at all because I'd just go home on the 
streetcar at night. 

I think we had a pretty good library system. Anything I 
needed, we had. 

Riess: And that was where you would have found the latest review and 
journal articles that were important to you? 

Schawlow: That would be in the physics library. As an undergraduate, I 
didn't really need to use that very much, but 1 did as a 
graduate student . 

I was also a member of the American Physical Society. I 
joined after I came back from World War II, but maybe even 
before that. We'd get the Physical Review, which had most of 
the important papers in physics, and the Physics Abstracts, 
which were then only about forty pages thick. I would read 
through the whole thing, at least skim through everything in 
all branches of physics. But now, a year's Physics Abstracts 
are, oh, about three feet long, something like that, and they 
don't give them away. If you're going to subscribe, I think 
it's something like a thousand dollars or more, so I gave up on 
it. But when I was a graduate student, I would read it all the 
time. Then if I needed to look up any of the articles, the 
library had a pretty good collection. 

Riess: You had said last time that you took a couple of the cultural 
classes. What did you take? 

Schawlow: In the first two years I think I took French. This was French 
literature- -it wasn't very profound and I'd had French in high 
school. It wasn't too difficult either. I also had to take 
first year scientific German, which again wasn't difficult 
because I'd had German in high school. In the third and fourth 
years I took Greek and Roman history. I think it was Greek one 
year and Roman the next. Very interesting, but I didn't really 
put a lot into those classes. I chose courses that did not 
require writing essays, because I was so tired of writing 
meaningless essays in high school when I had nothing to say. 
In that way, I completed a four year course at a good 
university without writing a single essay, although I did write 
lab reports. 

Riess: I wonder if you felt cheated of a certain kind of education in 
the humanities that could have been provided if they had 
systematically looked at physicists or scientists as people who 
were likely to be otherwise distracted. 


Schawlow: No, I guess I have an unorthodox view that I think if a person 
is good at something, you ought to let him do it and do it 
well. I think it would have been a shame to make Bach or Mozart 
study calculus. [laughs] Well, I am no Bach or Mozart, but I 
think one can pick up an awful lot of cultural stuff rather 
more easily than you can pick up science. You can read the 
reviews in the New York Times and other journals, magazines. 
I'm not widely read in the serious literature, and I don't read 
modern novels, but I think you can pick that stuff up more 
easily than you can science. Science was a full-time 
occupation, really. I found it quite hard. 

Riess: How about reading in philosophy? 

Schawlow: I have never done any, and what I've read hasn't made any sense 
to me, so I'm probably wrong on that. I'm really pretty 
ignorant of philosophy. 

Riess: At that age, or even an earlier age, what did you think about 

your possibilities? What sense did you have of knowing who you 
were? Do you feel that you knew, or were you floundering? 

Schawlow: Well, no, I think at each stage I wanted to take advantage of 

the opportunities that I had. As I think I said before, when I 
started out I thought, "I can probably end up teaching high 
school or maybe do something involved with radio." I didn't 
know whether I could go on to do graduate research for a Ph.D. 
or something like that, it really was something that I thought 
was beyond me. But I didn't really worry about it there was 
plenty to do. 

And then, of course, when I did well at the undergraduate 
work I thought maybe I could do graduate work all right, and I 
wanted to see how far I could go. I didn't know how I could do 
at research, not having done it. I thought it would be nice to 
do some basic science, basic physics--but I didn't know whether 
I could until I tried it. 

Riess: I think that scientists are blessed in that they often know 
that that's what they want to be doing, come hell or high 

Schawlow: I knew what I'd like to do, but I had seen the realities of the 
Depression. I was prepared to do whatever I had to do--but I 
knew what I wanted to do. 

Riess: To do whatever you had to do--in order that you be able to work 
in science? Was it like that? 


Schawlow: I guess it developed that way. Initially, it was just I would 
do whatever I would have to do to make a living. Because as I 
say, in the thirties during the Depression that's just what 
people had to do. But yes, I think by the time I was mid-way 
through graduate study I felt I wanted to go someplace where 
there was really front-line science going on and hope that I 
could learn enough to perhaps participate in that. 

There was a meeting of the Canadian Association of 
Physicists in Ottawa. This organization was formed about fifty 
years ago, wasn't it? No, 1945--I gave a talk at the fiftieth 
anniversary meeting. It was founded because a lot of 
physicists, people trained in physics, had done essentially 
engineering work during the war, and they were afraid that they 
would have to become registered professional engineers to 
continue in that sort of thing. So they formed this Canadian 
Association of Physicists to look after the professional 
concerns. Well, I joined the thing right away. I never was 
much interested in that, but I went to a couple of meetings and 
they had some physics talks as well as some talks about their 
worries about professional concerns. 

The meeting in Ottawa had a lot of dull talks about, as I 
say, whether they were going to have to register or whatnot, 
but I.I. Rabi from Columbia, who already had a Nobel Prize, 
came there and talked about the work that had been done 
recently in their department by Willis Lamb and Polykarp Kusch, 
who had unearthed new information about the nature of atoms and 
electrons in fact, a find for which they got a Nobel Prize 
shortly after. 

I thought Columbia was really the most exciting place in 
the world, and I really wanted to go there. I applied, after I 
got my Ph.D., to several universities, and I think I could have 
had assistant professorships at several places because there 
weren't many fresh graduates at that time in "49, but I did get 
this fellowship to go to Columbia to work with Charlie Townes. 

I didn't know about Charlie, and I wasn't much interested 
in organic chemistrythis was supposed to be for applications 
of microwaves to organic chemistry- -but I was interested in 
microwaves and had been for a long time, even worked on them a 
little during the war. And I was interested in them even 
before that. So, anyway, it turned out to be a very good 
thing . 

Riess: Yes. I guess the moral of the story was that that 

organization, the Canadian Association of Physicists, was 
perhaps a kind of watershed. It's horrible to think that if 


they hadn't formed that organization and Rabi hadn't come to 

Schawlow: I don't know, I think I would have known. I'm not sure. I 
think I would have because I did follow the literature quite 
closely then on what was going on. But it was one of the 
things that triggered it. 

Let me say one more thing about it. I gave this talk at 
the fiftieth anniversary and I explained about how it had been 
started--! didn't really go too seriously into it. But they 
printed my talk and they sent me a copy of their journal, and I 
see they're still worrying about the same problem of the 
professional status of physicists, which apparently has never 
come up in the United States at all. 

Riess: One of the things that you mentioned was that research money 
stopped during the war. Universities had to make a decision 
about research money or not. 

Schawlow: That was before the war, some time during the Depression that 

they had given up their research money. I doubt if it was very 
much, but they had an annual research grant from the 
university. Sometime in the Depression they were asked to give 
it up for a year and Professor Burton--Eli Franklin Burton, who 
was the head of the department at that timegave up the 
research grant for the year and the university didn't give it 
back. I know he must have been able to raise money somewhere 
because he had students build the first electron microscope in 
North America. That was a big advance and must have taken some 
money . 

Thoughts on Emigre Physicists, and Family Support 

Riess: A bit more on your early years. I wonder whether you had 
heroes in science. What about Einstein? Who were your 

Schawlow: Of course, everybody revered Einsteinextremely brilliant. 

It's hard for me to remember. Now I would think probably the 
person I would most admire was Faraday, from a hundred years 
earlier almost, who did such simple experiments and discovered 
entirely new phenomena. But I did read a lot about physics and 
physicists and I did admire the ones who had done some things. 
The theoretical stuff of Einstein's- -well, I don't think I had 
any illusions about being a deep theoretical physicist. 

Riess: Did you father or mother understand your interests? 

Schawlow: They were supportive. I never questioned them about how much 
they understood. I think they understood in a general way. 

Riess: But if you were coming home, sitting down at the dinner table, 
during the high school and certainly all those college years, 
did you tell them about what you were doing all day? 

Schawlow: Gosh, I don't know. I don't really remember. I don't think we 
would talk about specific physics problems. With my mother I 
talked about my general difficulties. But I can't remember at 

Riess: Do you think the family was very focused on your success? 

Schawlow: No, they were supportive but I don't think they were focused. 
Certainly they strained hard financially to get me and my 
sister through college. We were both there at the same time, 
and we both had had scholarships, but even so that was quite a 
burden. My father acquired some debts, I don't know how much 
they were. He never would discuss that with me. 

Fortunately, after the war he'd bought a house. They [the 
owners] wanted to sell us the house we were living in for 
$3,000, but we didn't think it was worth it, and my father 
bought another one for $6,000, I thinksold it a few years 
later for $15,000. Got another smaller one, and I think later 
sold that for $23,000. That was the only thing that got him 
out of debt. 

Riess: That's interesting. He put some work in on the house, or is 
this just general inflation? 

Schawlow: No, just the general inflation. The inflation of houses was 
very fast in fact, has been almost all the time since then. 

Riess: Was there a population of emigre physicists who came to Canada 
like there was in the states in the late twenties and thirties? 

Schawlow: There had been, but there weren't a lot around. There was a 
German physicist named Kohl who was a specialist in the 
construction of vacuum tubes. He gave a series of lectures on 
electronics. 1 listened to him twice, but it was unfortunately 
the same both times. Actually, he came to the Stanford area 
later and worked for one of the companies--! think also gave 
some lectures. But he wasn't right in the physics department. 

Let's see--oh yes, the most famous refugee was Infeld, 
Leopold Infeld, who had worked with Einstein on cosmology. He 


was Polish and he was professor of applied mathematics. I 
never worked with him. I heard some of his lectures, but 1 
didn't have a course from him either. 

Inf eld- -it's a sad story. He was Jewish and the Jews had 
been persecuted considerably even before the war in Poland, as 
in Russia too. But after the war he thought that the new 
government there, which was Communist, would improve things, 
and he wanted to help rebuild science in Poland. Well, the 
prime minister of Ontario was a Conservative named George Drew 
who kind of jumped on him for helping these Communists, and 
essentially made things unpleasant enough that Infeld left and 
went back to Poland. 

Riess: My question is partly why there weren't more, and whether the 
ones who came gave Canadian science a kind of jump start? 

Schawlow: I don't think they did. There weren't enough of them. 
Riess: They went to Chicago and they went to Caltech. 

Schawlow: Yes, Gerhard Herzberg went to Saskatchewan and then to Chicago, 
and finally after the war they brought him to the National 
Research Council. But he was never in Toronto except perhaps 
as a visitor. He was a preeminent molecular spectroscopist and 
got a Nobel Prize for that later. 

I think there was some anti-Semitism in the university. I 
never heard it talked about, but I don't think there were any 
Jewish professors in the university at that time. There are 
now, of course, but--. And that may have been another reason 
why they were not so keen to take in European refugees . It ' s a 
pity, because there were certainly some great ones available 
for almost nothing. 

Riess: You said your father chose to tell you that you were partly 

Jewish when you were seventeen. When you were seventeen it was 
1938, two years before the onset of World War II. When you 
think about it now, why do you think that he chose to tell you 

Schawlow: It's hard to tell. He had a sister who was still living in 
Latvia, and he was trying to see whether we could afford the 
money to bring her to the United States because he felt the war 
was coming. I think he decided in the end that we could not 
afford it, so I don't know what happened to her. But I think 
it was connected with that. I don't know, I guess he thought 
it was time I should know. I didn't react to it in any 
particular way, I think; it was a factnothing I could do 
about it one way or the other. 

Riess: In science, particularly, it's a really fine heritage. 

Schawlow: Well, I think also there was a Jewish tradition of supporting 

the son who was a scholarusually a scholar of Hebrew and that 
sort of thing, the Talmud. I think they treated me that way. 
1 spent a lot of time up in my own bedroom, studying or working 
on radios or something like that. They really were quite good 
to me, and I think they were generally supportive. There was 
never any question that I shouldn't go on as far as I could as 
a scholar. 

I wouldn't say it never entered my mind that I could be a 
scientist, but I remember my father saying more than once that 
I should study German because if I wanted to do serious 
science, I'd have to study in Germany sometime. Well, the 
world didn't go that way. In fact, we had young Germans coming 
to work with us. Later, I gave some lectures in Germany. So 
the thought that I might be a scientist was not entirely out of 
mind [pauses] but, I think I tend to concentrate on more short- 
term things. 

Graduate School Years The Master's Degree 

Riess: What do you mean you think you tend to concentrate on more 
short-term things? 

Schawlow: You know, I was wondering, sort of thinking back, "Why didn't I 
dig deeper into the textbooks and get more advanced books on 
science and so on?" Well, I didn't do that. I read all around 
it. I mean, I was very interested in things on radio in a 
qualitative sort of way, not really quantitative. And I read 
all the papers I could find on microwaves at the time when they 
were classified during the war. I found that the Germans had 
published more than the Americans or British had. I took those 
out of the library. 

Your mentioning libraries reminds me that our university 
library had a complete set of the philosophical magazine 
published by the Royal Society in England, and the first 
article in the first issue was "Mr. Cartwright's Patent Steam 
Engine Which Can Also Be Used as a Still." [laughter] I 
remember going into the library and looking around and looking 
through those old journals. They had a pretty good collection 
of old journals there. Of course, it wasn't as difficult as it 
is now because there are so many thousands of journals. Prices 
are so exorbitant. But they had a good collection of things 
that were published even before the university was founded. 


Riess: That idea, that maybe you were thinking short-term, or 
whatever, I guess it's a big mantle that gets laid upon 

Schawlow: I don't know anything, I think sometimes. But you learn a few 
things. As I'll probably say later on at the appropriate time, 
or maybe several times, I learned that to discover something 
new you never have to know everything about a subject. You 
just have to recognize one thing that isn't known, to look for 
the gaps. 

I think that really came to me, though not so explicitly, 
when I was midway through our graduate studies. Professor 
Crawford had told me to build this atomic beam light source, 
and we built it- -two other students helping, one had built the 
spectrograph. Then we had to decide what to do with it, and I 
did most of that work. I looked through the library to find 
out what atoms had not been studied with the kind of resolution 
you could get with an atomic beam light source. Finally, we 
did some work on silver, zinc, and magnesium. 

Riess: I was going to ask you exactly that. How had you kept up with 
the literature to decide what to work on with your atomic beam 
light source? 

Schawlow: Well, I fortunately knew enough German that I could read some 
of the old German papers the best work had been done in 
Germany before the war, and in England, too. You know, one 
paper leads to another. You get a reference, and it leads you 
to some earlier paper, and you can track things. The 
scientific literature is highly cross-linked becauseat least 
they have in the past felt responsibility to refer to all the 
relevant papers. So I did spend a good bit of time in the 
library at that point. 

Riess: [reading] 1 "In the United States [in 1927], many senior 

physicists watched the development of the quantum mechanical 
revolution with a sense of frustration. For some, the 
mathematics of the new formalism was simply too difficult. And 
all who were concerned with the philosophical implications of 
the new physicsparticularly the middle-aged men whose 
thinking had been formed in a more certain world were bothered 
by the seeming subjectivism of Heisenberg's approach." You 
went to a university where you probably were taught by a lot of 
"middle-aged men whose thinking had been..." 

'From The Physicists, The History of a Scientific Community in Modern 
America, by Daniel J. Kevles, Harvard, 1987, p. 168. 


Schawlow: Yes, I think so. Almost none of our professors actually used 
quantum mechanics. I didn't take the formal course in quantum 
mechanics, but I had some introduction in atomic theory. It 
was really very unfortunate that I never did because there were 
good graduate level courses. But by that time I was working in 
the light lab as awhat they called a demonstrator, here we 
call it a teaching assistant. And I couldn't get time off to 
take that course, so I never had a real course in quantum 

But I had the feeling there that people there really hadn't 
digested quantum mechanics for the most part. Crawford had and 
so had Welsh, I thinkbut they also were used to thinking in 
semi-classical ways, which could do a lot of the stuff. 

Riess: At the beginning of wartime, math and physics at Toronto added 
a specialization in radio science and technology. Was that in 
fact radar? 

Schawlow: Well, it was aimed for radar- -submarine detection, too, but I 
think mainly for radar. But I didn't go into that specialty. 
I remember asking the head of the department. He said, "Oh no, 
you know a lot about radio already "--which was true. 

Riess: So, onto wartime. That was your first teaching experience? 

Schawlow: No, I really didn't do much lecturing during the war. I think 
I gave one course, but mostly I was just a laboratory assistant 
or led discussion sections--one of the professors would teach a 
large class, and then the students would meet in smaller groups 
with some of us and we could answer questions or work out 
specific problems for them. And I think we helped them in the 
laboratory too. 

Riess: This is the army and navy guys? 

Schawlow: The army people were given our standard undergraduate physics 
course basically, which is a rather formalized, standard sort 
of thing. There were standard textbooks and standard topics 
that were covered, and it was pretty much the stuff we'd had 
earlier as undergraduates a few years earlier. 

The navy [chuckles] --well, they tended to be submarine 
detection technicians, and they were told that you had to have 
six months at sea and you don't get seasick, that's all that 
was required. So some of them came in not knowing much, and we 
had to do as much as we could with them. 








You're well very known for your demonstrations and I wondered 
whether you developed some of those techniques back then? 

No. But we did have at least one professor who gave very 
spectacular demonstrations in our first year physics class, 
mechanics. We had demonstrations in all the first couple of 
years physics classes, but Satterly, John Satterly, was one who 
really put on some pretty fancy demonstrations, especially in 
his liquid air lecture, in which he was following a tradition 
of the time when he was a student when people would go around 
putting on putting on liquid air lectures and demonstrations in 
the music halls or someplace like that, just as entertainers. 

Like a magic show? 

Yes, right. Because people were just not familiar at all with 
the strange properties. He did a lot of experiments, but one I 
remember: he'd put a loaf of bread in a great big pan about six 
feet across and then pour liquid oxygen on it, set fire to it, 
and the flames would reach up almost to the ceiling. It was 

Another one- -he'd dip a piece of rubber hose into liquid 
air and, of course, it got very brittle and you could crack it 
up like that. Then he took a couple of goldfish and put them 
in liquid air. Then he'd smash up one of them. The other one 
he'd put back in the bowl, and in a little while it'd be 
swimming around again. I asked him once, years later, how he 
could do it. "Well," he said, "you just have to be careful not 
to damage their scales." Anyway, those were spectacular sorts 
of demonstrations. 

It's interesting, they do connect to a tradition of magic. 

I don't know the specifics, but I have heard about it, that 
there used to be vaudeville people who'd go around doing liquid 
air demonstrations and talks. Of course, in those old pre- 
television days there were the Chattauqua lectures, and a lot 
of others in England. People would want to know about the 
latest discoveries of science in a digestible way--at least the 
wonders of science. 

Is it also the wonders of science and seances? 
of the century, weren't people seeking that? 

During the turn 

Some were. Oliver Lodge was a very fine physicist who became a 
spiritualist and spent a lot of effort trying to communicate 
with the dead--with no great success. 


Riess: Now, when you started to do your work for the MA degree, was 
that a time when you might have, if it had been at all 
possible, come to the States and begun your education here? 

Schawlow: Well, yes, but I didn't know what to do during the war. I 
guess when I started on my M. A. --probably '41--the United 
States was not yet in the war, but they soon were. Well, I 
just didn't have enough initiative to seriously consider going 
somewhere else at that point. 

Riess: Because you're really caught there on the fellowship issue, as 
you say. 

Schawlow: Well, at that pointthat was in '45 when that became apparent 
--my sister got a fellowship to go to Wisconsin to study 
English and she spoke to the physics department chairman and he 
assured her that they would gladly give me a fellowship to go 
there if I'd like to go. But things weren't going so badly in 
Toronto, and I thought--. I guess I tend to be rather 
cautious. In fact, I've probably missed a lot of good things 
by being too cautious. 

Riess: Was there also a pull to stay near the family? 

Schawlow: Yes, sure, I was living at home and my mother took good care of 

Riess: Well, I meant that you would be needed to take care of them? 

Schawlow: Not at that stage, no. They were still healthy at that point. 
They would be about fifty-five, I guess. 

Riess: Would you describe what you did for your master's? 

Schawlow: It was a silly thing. It had to be something applied and we, 
another student, Morris Rubinoff , and I were tryingthis was 
something we did while we were doing the teaching, you know, 
just in odd moments --try ing to develop a battery that would be 
activated when it was suddenly put in motion somewhere and 
spun. Well, we weren't told what it was for, but it was pretty 
apparent that it was for something to go into a shell. I 
learned later it was for a proximity fuse. So it had a little 
glass ampule and fins around the battery things. 

We didn't have any priority, we didn't have a lathe or any 
tool equipment. We could occasionally get a little machining 
done, but it was pretty bad. Actually, we got to the point 
where we fired one of these things off in a shell, sent it to 
Camp Borden, which is a training camp, and the ampule didn't 
break-- [laughs] whereas we'd dropped it on the floor and it 


did. I learned later that the trick was to put a little spring 
in the thing, make it so that it wouldn't break on a sudden 
impact, and make it weak enough so that it would break on a 
longer impactas in firing the shell. But we didn't think of 

It didn't really amount to anything, but after a year or 
so, they said, "All right, that's enough. You can have the 
master's degree." The master's degree was not anything very 
important. As Professor Satterly once described it, "It's a 
bone thrown to an underpaid demonstrator." 

Research Enterprises. Ltd., Wartime Research, the Bomb 

Riess: During those years was there an equivalent in Canada of Bell 

Labs, or a research laboratory associated with a communications 

Schawlow: Well, there was the Canadian National Research Council, and 

there even was a classified research program at the university. 
I don't know what they did, and I suspect that it wasn't much. 
The National Research Council in Ottawa did some radar 
development, but I think the level just wasn't really very 
high. And of course, I didn't get invited to join this group 
even in the physics department. I don't know whether it was 
because they thought I wasn't good enough, or because I was not 
a Canadian citizen, or because the professors who were doing 
the teaching wanted me. But I knew the people who were running 
that, and I doubt if anything very worthwhile came from it. 

Riess: The level of wartime research on the East Coast, at MIT-- 

Schawlow: Yes, if you went to MIT or Chicago or Columbia or Harvard very 
good things happened. They did move a lot of people from all 
over the country to theseand Los Alamos, too to these 
projects. But I suspect there were a lot of universities that 
managed to keep going in a small way, and not doing anything 
very important. 

Riess: Maybe since it was a British country all the research would 
have been sent off to England. 

Schawlow: Yes, the most important work was. People there still thought 
of England as the mother country and looked up to it. The 
people at the National Research Council did develop a microwave 
radar with a wave-guide antenna, which is what I worked on, 
trying to get in final shape for installation in the last year 


of the war at Research Enterprises Limited. But I think it 
really wasn't a very smart design. It was too sensitive to the 

Riess: Was Research Enterprises Limited formed because of the war? 

Schawlow: Yes, it was strictly a manufacturing company. They were set up 
during the war and they made. some optical equipment, including 
some teaching lab stuff --spectroscopes. They made rather nice 
spectroscopes, of which we had a few at the university. But I 
think mainly they made radar equipment . When I did go to work 
there, I saw one radar setup, a portable radar that required 
eight trucks, [laughter] I think a couple of them were spare 
parts or something like that. 

Riess: Did Canada get ahead of the United States in radar work? 

Schawlow: I don't think so. Britain did. 

Riess: I read that the magnetron- - 

Schawlow: That was British. 

Riess: And was the magnetron given to Canada for Canadian research? 

Schawlow: I think it must have been, but I don't think they did anything 
more than use it. They never published a set of books like the 
MIT Radiation Lab did to report what they had done. I guess I 
just never heard. 

Riess: Did you feel that you were involved in the war effort? 

Schawlow: Yes, but I didn't really think I was making a great 

contribution. I did what I was asked and I felt it was 
probably helpful for the war, but I didn't think it was going 
to make a big difference. 

Riess: You were testing components. 

Schawlow: Yes, basically. I worked at Research Enterprises during the 
summer of 'A3, I guess. And then in '44 I moved there after 
they finished courses for the army and navy at the university. 
When I was there for the summer we were testing transformers 
and capacitors. When I worked there, we were using these 
slotted waveguide antennas, trying to adjust them so that they 
would work. 


Slotted waveguide? 







Riess : 


Yes. It's a long piece of rectangular pipe- -oh what was it? 
about three inches by an inch and a half or so. And they had 
slots in the face that were supposed to be spaced a half a 
wavelength apart so that the radiation leaking through them 
would all be in phase in a forward direction so they'd get a 
good beam. These things were quite big, I think about ten feet 
long or so, maybe longer. We would check them in the lab and 
then mount them up on the roof on a turntable. Then we had a 
receiving station across the valley, a mile or so away, and 
we'd measure the pattern to see if they had a good directional 

These slotswe'd measure them first; the trouble is that 
the effective wavelength of the waves in the waveguide depends 
rather critically on the dimensions of the waveguide. And they 
weren't all that precise and so we'd measure one, measure the 
wavelength in the guide, have the slots put in, and then check 
it. But since it depended very critically on the dimensions 
of the waveguide, that is the width, if the temperature changed 
then that would change, and they would not work so well. I 
think it worked, but it wasn't really a very good scheme. 

That sounds very frustrating. 

Yes, well, I don't know, I didn't really try to improve it. I 
just said, "Okay, we'll do what we can with what we have here." 

Do you think that people, at some level, were in touch with the 
MIT Rad Lab? 

Oh yes, I think so. And with the British. I think in Ottawa 
they wereand maybe some of the people at Research 
Enterprises, but I wasn't. I did have a security clearance, 
but it was pretty low- level stuff that I saw. 

I'm trying to think about whether you would even have time to 
stop and think about this thing you were working on, and think 
in your mind about how it could be improved, or whether you 
were like a factory worker practically. 

I think I was more like a factory worker, 
creatively about it, I'm sorry to say. 

I didn't think very 

Well, do you think that that's you or do you think that's just 
the kind of nine-to-five nature of the job? 

I think it's probably both. I think it's probably the nine-to- 
five nature--! wasn't responsible for it any more than doing 
what I was asked to do, and I did that as conscientiously as I 
could, but I didn't really dig deeper. 


Riess: So you were doing that up until the end of the war? 
Schawlow: Just about a year, yes. 

Looking back, I probably should have studied physics while 
I was doing that, because we had to take qualifying exams for 
the Ph.D. on the undergraduate work and I felt it necessary to 
study for a year before I took those. Instead of taking them in 
the fall of '45, I took them the fall of '46. Of course, I 
started on the research before that, but nothing would have 
stopped me from studying for those exams while I was working. 
I wasn't being pushed that hard on the work. I could have 
worked on it at night but I didn't. 

Riess: Were you still being supported by scholarships there? 

Schawlow: No. During the war I was paid, not a princely sum but I was 

being paid for the teaching and later for the work at Research 
Enterprises. It was something like forty-five dollars a week, 
I think, for the teaching. Then when I came back there were no 
scholarships available, but I could get this teaching 
assistantship, or demonstratorship. 

Riess: And then that was the year that you studied for your exams? 

Schawlow: Yes, and I think I started planning on the research. I 

remember coming over to the university somewhere around the end 
of the war and talking with Professor Crawford outside the 
building about what I might do, and he suggested atomic beam 
light source. That sounded good because you could get some 
properties of nuclei, and what I really would have liked to do 
at that point was nuclear physics. There wasn't any 
accelerator and I couldn't get any closer to nuclear physics at 
Toronto than what I did. 

Riess: The A-bomb, where were you? 

Schawlow: Well, I really didn't follow it. I didn't really understand it 
awfully well. I knew that nuclear fission could produce a bomb 
with uranium. I think we knew even that uranium-235 was the 
important part. Oh, one heard rumors that there was work going 
on that. There even was an article in The Saturday Evening 
Post at one point, I think, that told something about it. But 
I didn't know where it was going on or what was being done. 

And I thought that you had to slow the neutrons down by 
putting them in water, because the slow neutrons had a larger 
cross-section. So I sort of visualized thiswell, they maybe 
would get some uranium-235 and dump it into the water, into the 
bay or whatever, and that would set it off. Of course, that 


wasn't at all the way they did it. They did it with an 
implosion. After the war, the Smythe report on atomic energy 
for military purposes was published and so then I learned 
something about what actually had been done. 

Riess: But that's interesting that you could 've even anticipated that. 

Schawlow: Well, the existence of nuclear fission was known, and as I say 
I think there was this article in The Saturday Evening Post 
about the possibility that one could make a superbomb that way. 

Riess: Maybe they were saying that the Germans were getting this 

Schawlow: Oh yes, they were very concerned about that. That's one reason 
people worked so hard, to beat the Germans to that. It would 
have been a horrible thing if Hitler had had atomic bombs. 

Riess: What do you think about the horrible nature of it anyway? 

Schawlow: I think it's pretty awful, and I guess I am sort of glad I 
didn't work on it. So far, everything that I've worked on, 
even when it's the military, has been rather peacefulfor 
radar, detecting incoming planes and missiles. I think it's a 
shame that they used the thing on people, but I can understand 
a little bit of the military mentality because they had 
estimates that so many hundreds of thousands or millions of 
soldiers would be killed if they had to invade Japan. 

Riess: Has it been an ongoing issue for you? 

Schawlow: No, well, I read the Bulletin of the Atomic Scientists, and the 
Federation of Atomic Scientists, wait a minute, it was the 
Federation of Atomic Scientists, now it's just the Federation 
of American Scientists it does very good work [publishing 
monographs] on trying to reduce the hazards of nuclear warfare. 
I think they were in the forefront of pushing to stop 
atmospheric testing which would pollute the atmosphere with a 
lot of that radioactive stuff. They're still working very hard 
to expose the nature of the dangers and try to get people to 
stop it. But I read the thing and I don't do anything about 

I have not been a political person or an activist. I can 
always see both sides of the question. I think if we hadn't 
had atomic bombs the Russians would have been even more 
aggressive in Europe than they were. In fact, one of the 
Russians told Charlie, "If you hadn't had the bomb, we would 
have done some things differently," or something like that. 

Riess: How about when Star Wars was--? 

Schawlow: Oh, that was just nonsense. In fact, I was quoted in Time, out 
of context, as saying something to the effect that I didn't 
think it would work- -whereas I would not have commented at that 
point, because I didn't know what secret work was going on. 
But I didn't really think there was any hope, and I was right, 
even though I didn't know the details. 

Riess: You get called upon for quotes, probably, a lot. 

Schawlow: Well, that quote was taken from some interview some months 

before. Somehow, they dug it out and posted it in Time. I was 
a bit embarrassed about it, but there was nothing I could do 
about it. 

I'm really rather pacificistic in my leaning. I think war 
is stupid, any war is stupid, because to kill people to settle 
a question is really not right. But on the other hand, I do 
see that some people are going to be very desperatethey want 
something and they'll risk anything for it. I was at a meeting 
in Canada and met a Canadian physicist who had been involved in 
political affairs, and he was talking aboutIndia had just had 
their first atomic explosion. I said I couldn't understand why 
they would want that because it would just makes them a real 

He said, "Listen, have you ever heard of triage?" I said, 
"No, I haven't." "Well, this is when you divide the wounded 
into three groups in a battle, and you patch up those that you 
can get back into action first; then, the ones you can get back 
into action later; and the rest you just let die." 

He felt that if there was a famine in the world India might 
be a victim of triage, and that's why they wanted to have their 
bomb. Well, that's his theory. Of course, they also have 
considerable enmity with Pakistan and China. It's a shame, the 
world will divide itself into groups, no matter whether they're 
based on race or anything else, but people will fight. Afraid 
I try to avoid that. 

Riess: Bomb programs are big science. 

Schawlow: Well, they're going to nuclear power. It has to be done. It's 
not really big science compared to the huge accelerators that 
they want to build nowadays, but it's pretty big. I, of 
course, held out great hopes for peaceful uses of nuclear 
power. The general line then was that power would be so cheap, 
they wouldn't even bother charging for it. They didn't realize 



all the difficulties, some of which are just due to unreasoning 
terror, I think. 

People don't know what's safe and what isn't, and they 
don't believe the government or the scientistswith some 
reason, government certainly has lied to us. But that means 
that they just paralyze. For instance, magnetic resonance 
imaging for the brain, and the body, is properly known as 
nuclear magnetic resonance imaging. However, they deliberately 
dropped the word "nuclear" because people were afraid of 
anything nuclear, thinking that had to with atomic bombs. 

In fact, risk is something that people are studying now. 

But you can't really ever get complete certainty in anything. 
It's funny, there are more people killed in automobiles than in 
wars, I think, but they tolerate automobiles because usually 
they're safe--"It won't happen to me." Of course, that's what 
soldiers, I gather, would tell themselves. "It won't be me." 

[tape pauses] 

Schawlow: I'm not sure what interest this part of the history will have 
for people. It wasn't until six or seven years later, 
actually, that we started working on the idea of a laser. I 
don't think people will be that much interested in what comes 
between, which is very different. We'll do it anyway, but I'm 
trying to think what Joe Public, Joe Sixpack wants. [laughs] 

Graduate School Years --Atomic Beam Light Source 

Riess: I'm interested in the trip you made to Purdue after the war. 
Was this was the first time that you'd even been out of 

Schawlow: Well, I'd been to Pembroke before to visit my aunt and her 
family and other relatives there. The first Canadian 
Association of Physicists meeting was in Montreal, and somebody 
had a car, another student. Several of us drove down there. 
The second one was in Ottawa. These were trips of at least two 
hundred or two hundred and fifty miles. But I don't remember 
having been on a train before that. 

The reason I went to Purduewhat happened was that we 
started on this atomic beam light source, and we read the 
papers of Karl Wilhelm Meissner and his associates who had 


built one of the first ones. I guess Minkowski and Bruck also 
had built one around the same time. 

Riess: Minkowski? 

Schawlow: Yes. And Bruck. I don't know whether it's the same Minkowski 
who did cosmology relativity theory. Probably not, but I 
haven't ever checked that. 

Anyway, we had a terrible time with it. I think we had a 
reasonable idea of how to go about it, but we didn't know a 
lot. There was nobody around there who knew anything about 
vacuum techniques. The electron microscope people, the ones 
who had built it, had gone, though it was still being used. 
But we had an awful lot of trouble with leaks. 


Schawlow: We shouldn't really have been using brass, we should have been 
using stainless steelalthough I don't know whether the 
workshop could have handled that, welded it. At any rate this 
thing was pretty big, between two and three feet high, and the 
ports, some of them were three inches in diameter. So when you 
evacuate, there's a lot of force from the air pressure on it. 

Riess: When you evacuate? 

Schawlow: Yes, you have to pump out the air. 

I should explain what the thing is. The idea is that you 
vaporize some substance, some atoms that you want to study. 
The atoms will go out in all directions, but you put a baffle 
in between that part where the oven isthere's an oven at the 
bottoma baffle that will only let those that are within a 
small angle go through. So you get a narrow beam. You don't 
get very many because you're throwing away most of the atoms, 
they go out in all directions, and you only take those which go 
through the hole. 

And then up above that we would bombard them with electrons 
and produce light, the idea being- -this is to get rid of the 
Doppler-broadening. That is, all atoms, if they're free, 
they're moving around rather quickly, so some are coming toward 
you and they emit a slightly higher frequency, shorter 
wavelength; others are going away, and since they're 
random, it just results in a broadening of the line which wipes 
out all the fine details that we want to study. 

I've often described this in lectures that it's like sound: 
if the source goes toward you [high-pitched voice] it goes up 



in pitch; if it goes away [low-pitched voice] it goes down in 
pitchtowards you [high-pitched voice], up in pitch; away, 
[low-pitched voice] down in pitch. That's the Doppler effect 
slightly exaggerated, [laughter] 

We were trying to build this thing to cut out the Doppler- 
broadening and I think our design seemed reasonable. After our 
first year, Fred Kelly came back from the war. He'd been in 
meteorology, I think, during the war. He did part of it and I 
did part of it, but we were having so much trouble with the 
leaks. When we'd get a leakwe didn't have a helium leak 
detector which were beginning to appear, but we did have a big 
tank, about five feet square, and we'd fill that with water. 
We'd take the apparatus apart and put plates over all the 
openings and blow air into the thing and look for bubbles. If 
you'd find the place you'd have it resoldered and then put it 
back together again- -and it'd take about a week for this and 
then something else would crack open! 

After a year or so of that I was getting pretty desperate, 
and I wanted to know if we were on the right track, so I wrote 
to Professor Meissner at Purdue and he very kindly invited me 
to come and see what he was doing. He treated me very nicely. 
I think I didn't tell him that I was a student, but anyway he 
treated me nicely and showed me what he was doing. And he 
offered me, if I wanted to come there, he could get me a 
research assistantship there. But I decided at that point that 
we were pretty much on the right track, and so I came back. I 
guess it was a little later that I got kind of disgusted and I 
insisted that the machine shop take it all apart and solder it 
more tightly, more strongly, and after that it worked all 
right . 

You financed the trip? It wasn't that Crawford sent you? 
No, he didn't authorize it or pay for it. I just did it. 
And what you were building was an atomic beam light source. 

Yes. The thing is that you could observe the fine details of 
spectra with suitable equipment, which the third member of our 
graduate student group was building, and you could measure the 
nuclear spins and the isotope shifts. Now they had measured a 
few things, but there were a lot more elements, and that's 
where I had to find out what wasn't done. So I had to read all 
the old papers and find out what was done and what wasn't done, 
and pick out some other atoms that we could vaporize reasonably 
and yet which had something interesting to look at. 








You mentioned that it had already been done in Germany, 
couldn't get what you needed from Germany? 




Well, this was after the war, of course, and the papers in 
Germany were pre-war stuff in the thirties and so on, so I 
doubt that any of them still existed. 

Is it also that you don't fully understand what you're doing 
unless you've built your equipment? 

[looking for papers] It does make a difference, but at least 
since then I've always felt, never build anything you don't 
have to. 

Is that tongue in cheek, or do you really think that too much 
time is spent on fabrication? 

Well, that saying, never build anything you don't have to, 
that's especially true because a huge instrument industry has 
grown up since World War II, and instruments have become much 
more complicated, and it just takes a lot of time to build 
them; if you're going to design and build a lot of the 
instruments, then you wouldn't have time to do the experiments. 

[showing interviewer] This is a diagram, from Fred Kelly's 
thesis, of the atomic beam light source. There was an oven 
down here, and then this was a water-cooled tank in the middle, 
cooling this tube. So that defines the beamanything that 
gets through here is pretty much directional. Now, compared 
with the atomic beams that are used in [I. I.] Rabi's lab, this 
is a very crude atomic beam. It gave us a collimation of 
perhaps one in ten, or something like that, but that would 
reduce the Doppler width by a factor of tenthe equivalent of 
reducing the temperature by a factor of a hundred. But you 
couldn't reduce the temperature of these vapors by that or 
they'd condense. So this was a way to get narrow lines. 

Is what you're doing optical spectroscopy, at this point? 

Yes, that's right. I didn't really pay too much attention to 
the optical equipment- -well, we did work on a spectrograph. We 
used what's called a Fabry-Perot interferometer. Meissner lent 
us one of his so we could copy it, and that was very helpful. 

You took the interferometer apart? 

We took it apart and had a copy made. The thing that's tricky 
about it is, you use two flat quartz plates that fortunately 
were left over from the 1920s. You coat them with some kind of 
highly reflecting metal, and then you set them up so that 


they're exactly parallelthey're very flat and exactly 
parallel to each other and this means a very fine adjustment to 
a fraction of a wavelength of light. The mount that Meissner 
showed us how to make was a way to do that, get them so they 
would be precisely parallel and would stay that way. 

We had some fun with the coatings on these. [laughs] We 
were working in the ultraviolet and there was just nothing on 
the ultraviolet. Nothing about the techniques for reflection, 
little information about reflection of thin films in the 
ultraviolet. I remembered reading- -the German ones in the 
thirties, Schuler and so on, said that they used the hochheim 
alloy, which was prepared by Dr. Hochheim of I.G. Farben. I 
don't know, I never heard of him after the war, but I even 
dreamt about it one night, that he said, "It's just aluminum- - 
just put it on good and quick." 

Riess: "'It's just aluminum- -just put it on good and quick.'"? 

Schawlow: Yes. Or was it "good and thick"? I'm not sure. There are 
various accounts of this. 

[William M.] Gray was older than we were; in fact, he'd 
been a demonstrator when I was a freshman, he already had a 
master's degree, but he had gone away during the war. He was a 
rather timid person. He built an evaporator where you could 
have both plates facing the source, which is a tungsten 
filament. You'd put some aluminum on it and evaporate it, but 
when you'd start evaporating the air pressure would go up in 
the thing; you evacuate as best you can, but then the air 
pressure would go up because gas is released from it, gas 
dissolved in the aluminum. So he did it very slowly and 
carefully, taking twenty minutes or so to evaporate a film, and 
the films were just terrible. They had very low reflectivity. 

Well, we had a visit about that time from A.G. Gaydon of 
Imperial College, London. He was a noted spectroscopist . We 
were telling him about this problem and he said, "Well, when 
Hilgers"--the famous optical company in England--"coats their 
mirrors, they just put on a little aluminum and blast it off." 
So then we wanted to try it real quick. But Gray was too 
cautious, he wanted to keep the pressure down. 

However, he was married, with one child, and a second child 
was about to be born, so he had to take some time off to take 
care of the first child. And while he was doing that Kelly and 
I took over the evaporator and blasted things off and got much 
better films. We actually published a paper on that. That was 
the first paper I ever published. Later on, electron 
microscope people studied the structure of the films and saw 


that they were different if they were produced fast. Basically 
what happens 1 think is that the vapor pressure of the aluminum 
goes up much faster than the evolution of gas, so that if you 
heat it good and hot, and fast, then the atoms can beat the air 
atoms to the substrate. Of course, ideally we should have had 
a super vacuum system. 

Riess: Did you have any idea at that time how much you were lacking? 

Schawlow: Yes, some of it, but we could do something with what we had. 
After we finished I did some work on silver, which turned out 
to be wrong, but we published it. 

The silver was a very fine structure pattern, and we 
resolved it, but there were two isotopes and they were very 
close together. We tried to identify the lines with the 
isotopes because one was more abundant than the other. Well, 
so help me, when we started out the published values were 
fifty-three to forty-seven percent. And that we could resolve. 
But I think that by the time we finished someone had 
redetermined that it was forty-nine to fifty-one. Well, we did 
it as carefully as we could, and we thought we had the one that 
was more intense, but later people got separated isotopes and 
found that we were wrong on that particular point. We did put 
in some other ideas there, though, that were worthwhile. 

Talking about evaporating metals, Kelly had to have a 
thesis, so we settled on magnesium and measuring the nuclear 
movement of magnesium. Magnesium turned out to be very, very 
hard to handle because every chunk of magnesium we'd get, the 
outgassing was just terrible, and we couldn't just blast it off 
with the atomic beam. We had to have a steady beam. It 
required, oh, about four hours exposure, something like that. 

There was a professor in metallurgy who had come recently 
to there from a government lab--I think it was Chalk River--and 
he had worked on a process for refining magnesium, and he had 
some chunks of magnesium that had been vacuum-melted. He gave 
us a few pieces, and with those we were able to do the 
magnesium. But with any commercial magnesium we couldn't do at 

One of the other problems that I may have mentioned in the 
notes that I wrote was that although this light source's 
electron beam gave a current of a whole ampere, it really 
wasn't very bright, and that is because we didn't have very 
many atoms when you have to filter them out and get only those 
going in a certain direction. I guess I didn't quite explain 
there that you have to have them in one direction because then 
you can observe them perpendicular to the direction of the 

Riess : 




beam, neither going toward you nor away from you, so you don't 
have the Doppler-broadening. At least, it's much reduced. 

We required, at least for the silver, exposures of about 
four hours at night--day or night. But if the air pressure 
changed, that changed the effective spacing between the plates 
and would blur out the pattern. The first solution, obviously, 
was to put the plates inside a box with quartz windows. We had 
to have quartz because it was working in the ultraviolet and 
glass doesn't transmit down there. Well, they couldn't afford 
to buy us a couple of quartz plates. They didn't have to be 
real good optical quality, but anyway, we couldn't get the 
quartz plates. 

We called up the weather bureau and found out--. We knew 
that we had to hold it within a hundredth of an inch of 
atmospheric pressure, a hundredth of an inch of mercury during 
exposure. And the only time where that would ever happen is 
between midnight and four a.m., because otherwise the daily 
variation of atmospheric pressure is much more than that. So 
we had to start out, get everything ready, and start the 
exposure at midnight. We were recording the data on 
photographic plates, and if anything went wrong, well, it was 
lost, but we had to stay on to vaporize all the silver or other 
metal because otherwise we'd crack the crucible when it would 
be solidified. So I'd be coming home at 4:30, 5:00 in the 
morning, and there aren't very many streetcars at that time, it 
was kind of chilly. 

It certainly was annoying not to have those few dollars to 
get those quartz windows, but we had to make do with what you 
could do. 

And Kelly and Gray were in the same straits? 


When did you have your Hochheim dream? 

It was about that time when we were thinking about the silver, 
the aluminum-coating of the plate. Now somebody, a friend, I 
think it was Pat Hume, another graduate student, had brought in 
a cartoon by George Grosz of a German Ph.D. looking very 
formal. So we put that up and labeled it Dr. Hochheim--but we 
had no idea what he looked like. 

It sounds like one of the best things about all this is that 
you were working in a team. 

That helped. It really helps. Gray pretty much Just worked on 
the spectrometer, which was fairly novel, and the Fabry-Perot 


interferometer. Kelly worked with me on the atomic beam 
source, particularly worked on the electron-gun, but we all 
worked on everything a little bit. 

Riess: Talking things out with somebody else is useful? 

Schawlow: Oh, yes, that's a big help. It really is. We didn't bother 
Professor Crawford much with these details, we sort of worked 
them out among ourselves. I remember Gray--he was sitting 
there one day just fuming, he really wanted to go and see 
Professor Crawford and say he couldn't do what Crawford had 
asked him to do in the way he asked him. I said, "For Pete's 
sake, just do it any way that works. That's all he wants." 
And he finally did it that way. He'd been around--he got his 
bachelor's degree I think in 1936, something like that. Here 
it was '46 or later, and he was just used to taking orders, and 
timid about trying something on his own. 

Riess: That is an important thing, and I guess you've had a lot of 

experience with that with your own students. How you get to an 
answerit doesn't make any difference? 

Schawlow: No. 

Riess: Efficiency is not a hallmark? 

Schawlow: Students are very different. I've had one student who was 

quite good, but he could not work alone at alland I really 
can't work very well alone, either. This one student, he was 
there for a year or so, just kind of fussing and fuming, afraid 
to do anything for fear of making a mistake. We had a visitor 
from France and they [the visitor and the student] did 
wonderful things in a few months. I said, "Well, just go on 
and do some more of that." Well, nothing happened until we had 
another visitor from Germany and they did some other things. I 
said, "Okay, you've got enough for a thesis now." Turns out 
this fellow has gone to Lawrence Livermore LabJeffrey Paisner 
is the name and he's now in charge of the planning for the 
giant national ignition facility. [See also Chapter V] 

Riess: National ignition facility? 

Schawlow: This is for thermonuclear fusion. They're trying to build it 
I don't whether it's authorized by Congress yet or not. They 
use laser fusion, where they have very high-powered lasers 
aimed at a little pellet of heavy hydrogen and heat and 
compress it enough that you get fusion of hydrogen atoms to 
produce helium. If you do that, you could get a lot of power 
out of it ultimately. But at this point they are trying to 
show that they can break even, get more out than they're 


putting in. They're not designing a reactor yet. 
huge project. 

That's a 

Riess: It's a nice point, that some people really need someone else. 
They cannot create an internal dialogue about a project? 

Schawlow: Yes, I think I need somebody. I really work much better with 
one or two people. At Bell Labs I had a technician who worked 
with me. I think I might 've done better if I'd been working 
with another physicist, but that wasn't the way we worked at 
Bell Labs. 

Riess: Before we make that leap, this first publication, did you get 
any kind of response to it? 

Schawlow: Well, the only thing I remember is that it was just a letter to 
the editor of the Journal of the Optical Society, which was 
something less than a page in length. One of the assistant 
professors at Toronto, David Scott, had taken over the electron 
microscope, and he did some electron microscope studies on 
films that were produced fast and slow, and showed the 
differences in the structure. So that was some response. 
Otherwise, I don't know. I guess Hilgers had produced good 
films and probably others too, but there was nothing very much 
out in the open literature telling you how to do things . 

[tape pauses] 

Schawlow: I was never really deeply involved in radar, except in that one 

Riess: Radar was so new? 

Schawlow: Yes, oh yes. It was a great surprise to the Germans. I heard 
that the British let it be known that they were feeding carrots 
to the night fighter pilots so it would improve their night 
vision, whereas actually they were using radar. That was a big 
surprise and a great help to the British in the Battle of 
Britain, although the Germans by the time were also working on 
radar. I don't think they had it in the airplanes at that 
point, but I really only know from reading some popular books. 
I wasn't deeply involved in it. 

Riess: In terms of the development of microwave work, was radar a 
necessary step? 

Schawlow: Probably- -although we had in the lab at the University of 

Toronto a klystron, which was quite new at that time. I think 
we had it before the war, or just about the beginning of the 




war. This is a low-power microwave tube, 
klystrons that are very high-powered. 

They now make 

This was developed at Stanford by the Varian brothers, 
Russell and Sigurd Varian. Sigurd was an airplane pilot and he 
wanted to do something to help prevent collisions of airplanes, 
so he thought if he had some kind of microwave thing, you could 
beam it. I guess he was thinking of collisions with the ground 
or mountains and that sort of thing. I don't think he ever 
actually did anything on the collision aspect of it, but he and 
his brother Russell had a little room in the basement of the 
old physics building and built the first klystron. 

During the war, they and some others went to the Sperry 
Company and developed klystrons for military work. Mostly low- 
power, I think. After the war they formed Varian Associates 
which developed very high-power things, millions of watts, 
which were used, I think, both in broadcast transmitters and 
linear accelerators, like the Stanford Linear Accelerator 

Did you know the Varians? 

No, I didn't. I never met them. They died before I came to 
Stanford, and I'd never been on the West Coast before 1961. I 
knew Chodorow and Ginzton, who had worked with them. Ginzton 
later became chairman of Varian Associates, but he was a 

professor at Stanford when I first came. 
Ginzton and Marvin Chodorow. 

You got your Ph.D. in 1949. 

[pause] That's Ed 

There's one more thing I want to say about the Ph.D. Many 
years later when I was in China, Shanghai, I was talking to a 
group of students and I couldn't resist saying, "Well, I know 
you're poor, you don't have all the equipment you'd like, but 
we were much poorer when I was a graduate student." [chuckles] 
We really were. I mentioned those windows we couldn't get. I 
burned out a ten dollar thermocouple vacuum gauge and they 
wouldn't buy another one and I had to take it apart and rebuild 
itwhich I guess was good experience, but--. 

I think the only research money they had was something that 
Professor Crawford and Professor Welsh had gotten. By working 
overtime teaching during the war they managed to get the 
university to put aside some money from their overtime pay for 
research, but it was very little. Fortunately, the university 
had been pretty good in the twenties and there were some things 
left over, like these very fine quartz plates that we used. 


Crawford and Welsh, and Women Students 

Riess: Okay, now I've read in several places, articles by you, how 

much you admired Malcolm Crawford. I want to be sure that he 
has been adequately covered. Why and wherefore? 

Schawlow: Toronto was so dead in the thirties. In the twenties it had 
been an active center under J.C. McLennan, and one heard all 
sorts of stories about him. He was a real autocrat and he got 
a lot of results, a lot of things done, but he drove away some 
of the brighter people. And during the thirties it was very 
poor due to the Depression, and the then chairman, E.F. Burton, 
tried to find jobs for as many people as he could and he 
encouraged them to take themand usually it was the better 
people who took them. 

But Crawford was a very independent-minded man and he just 
kept on doing research. They all had heavy teaching loads, but 
he still put in hours late at night and did some very nice work 
on basic atomic physics. He told me that he had written the 
first paper that showed that nuclei are not like electrons, 
that is they're not so-called Dirac particles, the angular 
momentum is not simply related to the charge. He did that by 
showing that the hyperfine splittings of the two different 
isotopes of thallium were not the same. They had the same spin 
had different magnetic moments, whereas two electrons will 
always have the same magnetic moment. Of course, this is 
something that is well known now, but it was at that time an 
interesting discovery. 

He would talk to us about things. I had some courses from 
him. He wasn't a good lecturer, he tended to write everything 
down on the board. It's a bad habit that I tended to acquire, 
[laughs] But he was clear and he would talk about the basic 
physics. And also when you would talk with him he would 
discuss and speculate about what he thought might be important 
in the future. He was a little man, fairly short, but very 
intelligent and extremely hard-working. He unfortunately died 
of a heart attack at the age of about fifty-five or something 
like that. 

Riess: Besides you, did he turn out, a number of-- 

Schawlow: Oh, a huge number of students, particularly after the war. 

Riess: In atomic physics? 







Well, a moderate number in atomic physics. But he was also 
working on molecular physics. And after the war there was a 
flood of graduate students. 

Another professor, Harry Welsh, was a slow developer. He 
had a very bad stutter and Burton wouldn't let him lecture. So 
he just was running the advanced student laboratory. However, 
during the war they were desperate for teachers, so he started 
to lecture, and he was a very good lecturer. He was slowed 
down by his stutter, but I think if he hadn't had the stutter 
he would have been too fast. But he was very clear. I took a 
course in molecular spectroscopy from him. He also had many 
students, all in molecular spectroscopy. 

He later became a big wheel. I think he was head of the 
department during the period of rapid expansion in the fifties 
and pushed to get a new building, which they did, and build up 
the department, really rebuild it. They had several department 
heads after Burton, and they were flops. But Welsh took over 
and did a great job. He had an awful lot of students. I think 
Crawford had about half a dozen before me, before the war, and 
so on, but I think he must have had at least as many after the 
war in atomic physics, putting a lot of his effort into 
molecular stuff too. 

I noticed one woman in your class picture, 

How far did she 

Very sad story, I probably shouldn't say it. She did go to 
McGill. I don't know what she did during the war, but after 
the war she got a Ph.D. from McGill in microwave spectroscopy. 
And she published one paper, which was totally wrong, and then 
she got married to another quite distinguished astrophysicist-- 
his wife had died. They married, and I suppose she had a good 
life after that. But it's a pity--this one paper was just so 
transparently wrong that I didn't want to refer to it. What 
she had done was, she had observed a series of equally-spaced 
lines in the microwave spectrum of ethyl alcohol, and these 
equally-spaced lines were quite obviously the resonances in the 

So this one time was it? 

I don't think she did any more after that, yes. I think she 
probably did a reasonable experiment, but whoever was 
supervising her didn't catch that. I think again probably it 
was that McGill--they were starting up after the war and had a 
huge number of students, and they didn't have anybody who knew 
that field. When I saw her paper I was working with Charlie on 
the book and by that time knew something. 

Riess: It was probably was unusual even to have one woman. 

Schawlow: Yes, well, we had about four to start. I think one other 
finishedGrace Smith. 

Riess: Now are we talking about graduate or undergraduate? 

Schawlow: Undergraduate. Graduate years, there weren't any in our group. 
There were some women around the physics department who had 
Ph.D.s, but they were in very lowly positions or just 
demonstrator, which is the sort of teaching assistant. I think 
eventually they got to be professors, but it was a long time 
coming. I think it was Welsh who pushed that through. 

One of them, only one of them, Elizabeth Allin, did 
research. Crawford got her active again and she published some 
papers. She knew physics well. We had her for a modern 
physics course in our senior year of college. But I think she 
had sort of given up until Crawford got her back to work on 
research. She's still alive, I've had a couple of letters from 
her, but she's over ninety now. 

Riess: I was wondering whether the war years were an opportunity for 
more women? 

Schawlow: Well, yes, the only other one was this Elizabeth Cohen, who 

took that picture of me. She had a Ph.D., I'm not sure in what 
field, and she was employed in teaching during the war. I 
guess she must have been around after the war because that 
picture was taken in 1949, I'm pretty sure. So she was 
probably a lecturer or something like that. 


Riess: The picture from your undergraduate yearsit's a strikingly 
homogeneous body of people, unlike anything you'd ever see in 
California. Were there any Indian students or anyone from the 

Schawlow: Not undergraduate. Graduate years, we had a student from 

India, we had a Catholic priest from Quebec. Both of those 
are, well, semi-sad stories. They had to get through in a 
certain number of years, I think it was two or three years. So 
they did, with a bit of a push, but then they never did 
anything more scientifically. The Indian, Manual Thangaraj , 
was from Madras, I think, that is, southern India. He became 
president of Madras Christian College, so he must have had a 


good teaching career. But I think he didn't do anything in 
research after that. A lot of them didn't. 

It was not a place that attracted people internationally. 
It really wasn't that good. I think it became so later, but-- 

Riess: So that anyone who was a colonial could have gone to England, I 

Schawlow: Well, that was considered the great thing. You could get these 
1851 Exhibition Fellowships to go study in England, but I 
wasn't eligible, not being a British subject. I don't think it 
would 've been good, anyway. 

Riess: Why? Wasn't Cambridge the best thing? 

Schawlow: Cambridge was. Oxford was very good, post-war years. Yes, 

they were pretty good places. But the particular things that 
were going on therewell, I could get interested in lots of 
things . 

Riess: What you were doing in your graduate years set you up so 
perfectly for what you have continued to do. 

Schawlow: Yes. It worked out well. Unlike Charlie Townes, I don't plan 
my career very well, I just kind of take advantage of what 
opportunities I can see. 

Well, yes, it has worked out, in the end it did, but 
really, I went through a lot of other things. Microwave 
spectroscopy is quite different from optical spectroscopy, but 
of course, I'd been interested in microwaves so it wasn't so 
hard. But then I worked on superconductivity, and that had 
nothing whatever to do with what I had done before. And that 
was difficult, I wasn't well prepared for that. 

Then, of course, we did fortunately get ideas about lasers 
and I was able to get back to optical spectroscopy and lasers. 
Now there I've had a very good background for it, having both 
radio frequency and optical work, because the radio frequency 
ideas carried over into lasers. 

Riess: In the Nobel Prize description of you, it says your thesis made 
you aware of "the need for a coherent, narrow-band source of 

light with which to analyze the structure of atoms..." 1 
very tidy. 

So it's 

The Nobel Prize Winners In Physics, Salem Press, Pasadena 1989, 







Yes. That's true. I used to wish I could just reach out and 
grab those atoms and make them stand still. [chuckle] But 
they wouldn't do that. If they're free, they're bouncing 
around . 

Is that an image that you really had? 

Yes, I had that. Of course, many, many years later we found 
ways to slow them down with light, laser cooling, which we'll 
come to. Since then other people rather soon learned to trap 
them, so they really can hold them practically still and get 
them very, very cold so that they have almost no motion. So 
they can observe them for a long time without any disturbance 
from the motion of the atoms. 

That's neat, essential, I suppose, 
so physical that you can- 

that sense that the atom is 

Picture grabbing it, yes. You couldn't grab it, though, 
because you'd have to hold it some way, and that would disturb 
it. They now have traps, however, which can provide minimal 
disturbance to the atoms. That's another one of those-- 

Well, my three most important papers, really, have been 
ones where I put in ideas, theoretical ideas, of a low caliber 
as far as mathematics is concerned, which were important: the 
one I mentioned on the properties of nuclei where you can take 
seriously the nuclear size correction; and the second one was, 
of course, the laser paper, the optical maser paper; and then 
the laser cooling paper. I did that with Ted Hansch, who was 
then at Stanford. He's been here the last week. He's going 
home tomorrow. That's H-A-N-S-C-H. His name is Theodor, but 
he insists is Tay-o-door--doesn' t like being called Theo or 
Theodore, so he calls himself Ted. 

That paper was what year? 

Nineteen seventy-five. Nothing happened about that for about 
six years, I think. Then Steve Chu, who was then at Bell Labs, 
sort of rediscovered the idea, and later realized that we had 
already published it. But he actually did it, and it's a 
rather difficult experiment. We didn't do it at the time, 
didn't try, because we were very much concentrating on 

Our interest in hydrogen was because it's the simplest 
atom, and therefore the one that you can compare with theory 
most closely. Ted was and still is working on hydrogen, but 
hydrogen requires deep ultraviolet light and there wasn't and 
still isn't a suitable laser for cooling it. You could cool 


atoms like sodium that emit and absorb visible lightbut I 
guess I shouldn't get into laser cooling any more at this 



Carbon and Carbide Fellowship 

Schawlow: I was just a young student and Canada was a backwater then, I 
really felt it. By the time I got toward the Ph.D. I felt 
maybe I could do some good science. But all the way I had 
never considered becoming a Canadian citizen because I felt if 
I was going to do science I would have to go to the United 
States. There's some pretty good science in Canada now, but 
there wasn't at that time, really. It was really not up to 
international standards. 

Riess: Okay, I hope you will now continue the story of hearing Rabi 
lecture, and talk about Columbia. 

Schawlow: Well, I guess there's not much more to say: I went to this 

meeting of the Canadian Association of Physicists in Ottawa, 
and most of the talks were about the right of physicists to 
practice as professional physicists or engineers. I thought 
that was pretty dull, but Rabi gave an invited talk in which he 
talked about the recent discoveries which led to quantum 
electrodynamics, and really was new physics. 

I thought that was really quite exciting and that I really 
wanted to go to Columbia, so I wrote to him when I was 
finishing up and he suggested I apply for the Carbide and 
Carbon Chemicals post-doctoral fellowship to work on 
applications of microwave spectroscopy to organic chemistry, 
with Charles Townes. As I say, I didn't really know his work 
at the time. I should have, because we did have a seminar and 
some of Charlie Townes' papers had been discussed in there. I 
had an atrocious memory for names and didn't make the 



Schawlow: An amusing thing, I don't know how it ever happened, but we had 
a neighbor a few doors away who worked for Carbide and Carbon 
Chemicals, and he asked me to come over to his place and sort 
of interviewed me. Somehow, I was being considered for this 
fellowship. I don't think that Carbide and Carbon Chemicals 
Corporation really had any say in the thing, but somehow or 
other he'd gotten word of it and decided he should interview 

Riess: In fact, did you ever have to report back to them? 

Schawlow: No. I was the second fellow of this type. The first one, 

they'd had him visit their plant in West Virginia, I think, and 
he gave a talk, and they found it hard to believe what he was 
telling them, though it was true, namely that the peak strength 
of the microwave absorption line in a gas doesn't depend on the 
concentration, on the pressure, the reason being that it 
broadens just as much as itthe total intensity goes up, but 
it broadens so that the peak intensity remains the same. And 
they found that hard to believe. 

The history of that fellowship: it may be that Charlie has 
told about it, but Helmut Schulz was a chemical engineer with 
Carbide and Carbon Chemicals, and he had a lab accident that 
had damaged his eyes, he was almost blind, so they put him in a 
position to do some long-range planning sorts of things. He 
had the vague idea that one could control chemical reactions by 
some kind of radiation that was longer than visible light but 
shorter than radio waves, something in the infrared 
essentially. But there was no good way of generating those 
infrared waves . And so he looked around to see where they 
could put some money that might advance that . 

At Columbia Charles was working on the interaction of 
microwaves with molecules. They also had the radiation lab 
there that was still working on millimeter wave magnetrons, so 
they were working on molecules and short wavelengths. So they 
decided to give the money for a post-doctoral fellowship at 

Riess: Did you meet Schultz? 

Schawlow: Yes, I did. I met him several times. Nice guy. In fact, he 
showed up a few months ago. He's now pretty old, but he was 
coming out with his wife, visiting various places. He managed 
to drop in and we had a nice chat. 




So he was the one that brought us together, and in a way 
this sort of thingthe fact that we were together--led 
eventually to the laser, which does give you a potent source of 
infrared. But I don't think controlling chemical reactions has 
really been very successful in the infrared. It's partly much 
too expensive because photons are expensive to generate, and 
most chemistry is done in batches of tons and sells at cents 
per pound. Laser photochemistry has been used to separate 
uranium isotopes which are, of course, very valuable, and while 
that's expensive it is cheaper than other methods of doing it. 
I didn't work on that. 

When we thought of the idea of a laser, the only 
application I had in mind was this thing that Schultz had 
suggested, maybe control chemical reactions, because it's 
obvious that chemical reactions usually go faster if you heat 
them up and here is a very selective way of heating them up. 
So at Stanford I had one student working on trying to separate 
bromine isotopes, and we were able to get a selective 
initiation, but the isotopes were scrambled before the reaction 
was completed. What I didn't realize was that if you were 
going to do it you had to do it very fast, so that you complete 
the process before some competing collisions scramble it all up 

After Tiffany did his thesis and leftthat's William 
Tif f any other students didn't seem interested in doing what 
was clearly chemistry, perhaps not so much physics. Also I 
began to worry a bit about the separation of uranium isotopes; 
I didn't want to do anything that would speed the day when it 
would be easy to make bomb materials. So I decided I just 
wouldn't work on isotope separation anymore, other people could 
do it. It's okay for labs like Livermore where they have huge 
facilities and some secrecy, but it's quite possible that I 
might have discovered a way to do it cheaply in a garage or 
something like that, and that would be horribleand terrorist 
organizations and criminals could get atom bomb materials. 

That's about the only time I ever steered clear of any 
subject for any ethical reason, but it was partly because 
students didn't want to do chemistry, and I guess I didn't 
either, to tell the truth. 

But they hadn't focused on the ethical issues themselves. 

I don't think so, no. But of course, bromine was quite 
different from uranium and had no applicability. 

So you've described the intent of the fellowship-- 


Schawlow: In fact I was just another person in Charlie Townes 1 lab, where 
he was working mostly on organic materials. But he asked me to 
try and see if I could detect the spectrum of a free radical 
OH, that is one oxygen atom and one hydrogen atom. It's 
interesting that even then his real interest in it was for 
astronomy, because he thought there ought to be OH out in 
space. He thought if we could detect it, it would be an 
interesting probe for the conditions around stars. 

I had a hard timeagain, I didn't have the equipment I 
needed and that I knew I needed, although they had an awful lot 
of microwave equipment. Trouble is that you could find out 
pretty quickly that OH can be produced in a gas discharge. I 
made a spectrometer with a long tube that we could run current 
through to get a discharge, but then the trick was to know when 
we were producing any OH. The difficulty was that we could 
have done it very well if we'd had a good spectrograph, because 
the spectrum was at that time was well knownit's in the 
ultraviolet, it was known but we didn't have one. 

Columbia had sort of missed the boat in the twenties. It 
had been pretty moribund and didn't have a lot of spectroscopic 
equipment lying around. And Charlie didn't feel like buying 
one. So we tried to use a chemical test that was published 
that said that if you have OH, you'll produce hydrogen peroxide 
if you let it condense on a cold finger cooled by liquid air or 
something like that. 

Riess: On a cold finger? 

Schawlow: Finger. Yes, you take a jug of liquid air, a canister that 

contains liquid air, have a tube going down at the bottom which 
sort of looks like a finger. You let the stuff condense on 
that, and it's cold enough that it will condense. Well, we got 
lots of hydrogen peroxide, but with still no OH spectrum. 

I did some other things with people in the lab. I had a 
student working with me, Mike Sanders, T.M. Sanders, Jr. He 
was quite good, but we didn't get anywhere. We used an 
ingenious spectrograph: instead of using electric field 
modulation we used a magnetic field, wrapped a coil around the 
long tube, and put an alternating current through it so it 
would produce alternating magnetic fields. We thought that was 
clever, but Walter Gordy at Duke had done the same thing about 
the same time and published before us--he used it for oxygen, 
which is also magnetic. Whereas normal atoms are not, or 
molecules; it's just the occasional one like oxygen, or the 
free radicals would be magnetic. 


I was there two years, and after I left Sanders and another 
student were working there one night when something went wrong 
with the discharge conditions and they happened to be sitting 
at the right wavelength and saw the absorption lines. So this 
hydrogen peroxide test was just a wrong way to tell whether you 
had OH or not. Of course, once you have the microwave spectrum 
then it's a good test. But I've always regretted that I didn't 
have an optical spectrograph to test whether I had OH. 

[tape interruption] 

Charles Townes and the Microwave Spectroscopy Book 







I thought Columbia was where microwaves spectroscopy was going 
on, but they didn't have the equipment you needed? 

They had microwave equipment, lots of it, but they didn't have 
the optical equipment that I needed to go with it. 

And yet, between you and Charlie, you really wrote the book 

Yes, he asked me to stay on and help him write the book on 
microwave spectroscopy. So 1 did stay for a second year. The 
fellowship was only good for one year, but he got some money 
from the Ernest Kempton Adams Fund, I think, that Columbia had, 
to support me for another year. The department had suggested 
that I might want to be an assistant professor, but I said I 
just couldn't see how I could teach, do research, and write the 
book, so I turned that down. 

It was a book that was ready to be written? 

Well, it's funny. Charlie Townes really wrote the book. He 
wasn't the only one working on microwave spectroscopy, but he 
was one of the leaders. Walter Gordy at Duke, and M.W.P. 
Strandberg at MIT, and D.E. Coles at Westinghouse, those were 
the main ones. And there was quite a rivalry between Charlie 
Townes and Walter Gordy at Duke. Some book salesman came and 
told him that Gordy was going to write a book, and so he 
decided that he would write a book too. [laughs] I think 
everybody agrees that it was a better book because Gordy was 
sometimes a little slapdash. 

But anyway, he asked me to help him on it and so I did, I 
stayed another year, which was good because that's when I met 
my wife, Charlie's younger sister. 










Let's step back a little bit to have you describe this time. 
It's very fabulous for me to imagine you leaving Toronto and 
coming to the big city. How did you find a place to live and 
how helpful was Charlie? Was Charlie really in your life at 
the beginning, or were you just anybody? 

He was very nice to me, invited me over to have dinner once or 
twice. At one time, they permitted research associates to join 
the faculty club. Since they didn't have anywhere else to eat, 
I often did eat over there. I got to know some of the 
professors that way, both in physics and mathematics. 

And where did you live? 

When they notified me of this fellowship, they said that I had 
to live in the university dormitory. I think that was not 
really correct for post-doctoral fellowships, but not knowing 
any better I took a room at a John Jay Hall, which I found 
rather annoying, but I didn't know any better or what else to 
do. I was there for about a year and a half. The thing I 
didn't like was the walls were rather thin, so I couldn't play 
my records very loud, or even what I consider a moderate 
volume, or I'd get complaints. 

Also, in New York City and in John Jay Hall they had direct 
current. It was a legacy of Edison, who didn't believe in 
alternating current. It meant that any kind of radio equipment 
wouldn't work unless you got a converter, which I did. I bought 
a converter, a kind of a vibrator that converted DC into AC, 
but it really wasn't very satisfactory. 

You came down from Toronto by train? 
Yes, I did. 

You packed up a wardrobe and your records, 

What else did you 

Did I take records with me? I guess I took some records, and 
of course I bought more in New York. I probably brought the 
record player, too. Some books. 

Were there any formalities of reestablishing your citizenship? 

Yes. There was a little bit. I went to the U.S. consulate in 
Toronto and presented my birth certificate and said, "Is it 
okay? Can I go back?" And I said, "No, I'd never voted in an 
election in Canada." They said, "I guess that's all right." 
Actually I think I could have crossed the border without 
bothering with any of that stuff. 


While I was there I registered to vote in New York, and it 
was quite amusing, I was told that if you had a high school 
diploma you didn't have to pass the literacy test, but a 
college diploma only proved that you could read Latin. So I 
had to take a literacy test which of course was not difficult. 

Riess: Did you go back to Toronto for your holidays or had you really 
made a break? 

Schawlow: I went back for vacations, some. I did go back several times a 
year, and I started to go by plane. The first Christmas 
season, I think, that I was there, I went back by plane. And 
then the weather was so bad I had to come back by train, 
because the plane wasn't flying. 

I felt very lonely at first. Although I'd never been a 
great lover of gardens or trees and things, I really missed the 
greenery. In New York, it was all concrete practically. But I 
got to meet people. I joined the Riverside Church and they had 
a young people's club that I went to, so I got to know a few 
people there. I got to know some of the graduate students at 
Columbia pretty well, too. 

Riess: And did you get right onto the jazz scene? 

Schawlow: I went out there occasionally, yes. I'd visited New York a 
couple of times when I was a graduate student. I knew where 
the places where, and I would go out occasionally. I couldn't 
go very often because it meant staying out very late at night. 
They used to close at three a.m. in those days. You'd come 
home on the subway at three o'clock and see people like milkmen 
going about their business. Nobody would bother you at all. It 
was really a nice place. 

There were some stores that specialized in jazz records. 
It was interesting--! 'd found this the first time I'd visited 
there, in '47, that these stores, unlike the ones in Toronto, 
knew exactly what every record was worth- -usually priced a 
little bit more than what I would pay. The ones I would pay 
more for, they raised the price. They knew exactly what they 
were all worth. 

Riess: You were filling in your collection? 

Schawlow: Yes. And expanding- -building a jazz record library. 

Riess: Has that been a lot of what being interested in jazz has been 
for you, is to create a complete archive? 


Schawlow: Yes, within certain ranges. I mean, obviously I can't get 

everything that's been done, but for the major artists that I 
really liked and admired, I try and get everything I can. I'm 
really missing it now: I had complete sets of Tommy Dorsey, 
Artie Shaw, and Bennie Goodman that were issued on Victor Blue 
Bird label a decade or so ago. I put most of those on mini- 
discs and I cannot find those mini-discs now. I'm feeling very 
frustrated. They're out of print. 

Riess: You'll find them. 

Schawlow: Maybe. Or they'll reissue them. 

Riess: The Riverside Church, you had your music life, you had some 
friends, but the question of whether to stay on the second 
year: if you hadn't stayed on the second year, what was going 
to come up next for you? 

Schawlow: Actually, the University of Toronto contacted me and another 

fellow, this Pat Hume that I mentioned before, who had gone to 
Rutgers about the same time I went to Columbia, and they asked 
us if we'd be interested in an assistant professorship. I 
asked if I could postpone it a year because I'd already 
promised Charlie that I would stay and help with the book. 
Well, that didn't work out, so he [Hume] took the job. I 
probably might have gone back to Toronto if there hadn't been 
anything else in sight. 

Riess: Did you go out to Brookhaven when you were in New York? 

Schawlow: No. I didn't. Charlie was there during the summer, just 

before I went there. In fact, he was still there over Labor 
Day weekend. He invited me and my predecessor Carbon and 
Carbide Chemicals fellow to go out there. I got a most 
horrible sunburn. 

Riess: I've a note that Charlie was extraordinarily effective in 

getting the best from students and colleagues. How would you 
describe how he worked with you, for instance? 

Schawlow: I don't know. He would make suggestions, but he didn't 

supervise me very closely, not on a day-to-day basis. He had 
weekly meetings with his graduate students and they would 
present some aspects of their research to be discussed there, 
and I think that helped to stimulate. He had a large group so 
they sort of supported each other in some ways; they could 
discuss things with each other. 

For me, well he suggested various things. After I'd been 
there for little more than a year, and I was still stuck on 


this OH experiment, he had me help some other students on other 
projects so I'd get some publication before I'd have to leave. 
I did that. I wasn't terribly interested in it, but I did what 
I had to do there. I really still wanted to struggle with the 
OH, because that was the first free radical that was found with 
microwave spectra. 

Riess: Working on the book sounds like it could have derailed you. 

Schawlow: Yes, it did some. The trouble was I was not an expert on 
microwave spectroscopy at all. I really wasn't. I'd been 
there only a little over a year when we started on it, so I 
sort of drafted several chapters that seemed like they were not 
too specialized. I did chapters on atomic spectra and diatomic 
molecules, and then later on pressure broadening and on 
millimeter wave techniques. But I had to study these up, each 
one, because I really wasn't an expert on microwave 

Riess: It sounds very uphill. 

Schawlow: Yes, it wasand then it kept on and on. We didn't finish it 
while I was there. The next three years, I think, I would go 
in many Saturdays and work on the book while I was at Bell 
Labs. It was a distraction all right, but I felt from the 
beginning if we were going to write a book at all, we wanted to 
write a classic that would be something that everybody would 
respect and turn to, and I think we did. It's been very widely 
used and quoted. I think, frankly, Charlie's part was the more 
important part, because he knew the stuff and I didn't. But I 
did study up some and wrote some of the things . 

Meeting and Marrying Aurelia Townes 

Riess: Before we finish for today, and since we're being very strictly 
chronological, when did you meet Aurelia Townes? 

Schawlow: It was in the fall of 1950. I went to Columbia in '49 and I 
was there for a year, and I was frankly beginning to look 
around a little bit to see if I could meet a nice girl, and I 
never took one out more than once. And then she came by my 
lab, he brought her around. He'd brought his older sister Mary 
before and I didn't pay any attention to her. They kind of 
looked in the door and I figured, well, his sister is probably 
older than me, I didn't really take a good look. 




Riess : 




Then Frances [Mrs. Charles Townes] invited us to dinner and 
made sure we got to know each other and we started going out 
together. It wasn't very long before I proposed. She took a 
little while longer to decide whether she wanted to do it or 
not, but by January I think we were engaged. 

Was she already living in New York for her music study? 

She had been there before to study singing and music in 
general. She'd gotten a master's degree in music education 
from Teacher's College, and she'd come up this time to take 
more studies, mostly with a private teacher, Yves Tinayre. She 
did take some courses at Julliard and at the Mannes College of 

She was seriously pursuing this career? 

Yes, as a singer. But it's a very hard, competitive field 
which she eventually gave up when we got married, pretty much. 
Well, she was still going in to New York to work with a pianist 
and an accompanist. We moved to New Jersey after a year, in 
September of "51, I think it was, when I started work at Bell 
Labs. And she was still going on the train to work with her 
accompanist and also take lessons from Yves Tinayre. 

What were your impressions of the Townes family when you met 

They were very nice to me. It was a bit overwhelming to meet 
all of them at once, but I guess Charlie had said some good 
things about me and they were quite nice to me. 

South Carolinawere they terribly southern? 

Pretty southern, but they were all very intelligent, and most 
of her brothers and sisters had studied in the north somewhere. 
I think two of them had studied at Cornell and two at 
Swarthmore. They were southern all right, but I wasn't 
particularly prejudiced against southerners, which a lot of New 
Yorkers were. They were something really just outside our ken 
in Toronto. We'd heard about southerners, and we'd heard about 
lynchings. I think it was Mike Sanders who said, "When you 
meet her father, just ask him, 'Have you seen any good 
lynchings lately?'" 

I'm very ignorant about the south, but I love the accent. Did 
she have an accent? 

She did sometimes. She could sort of turn it on and off. 
depend on the circumstances. 














Did you get married down there? 

Yes, we did. That was the first time I met them. 

My mother came along and we flew down. At that time the 
only plane was a propeller plane, of course, and unfortunately 
I think it stopped about five times. They served potato salad 
for lunch, and just after the second to last landing it came 
up. [chuckle] I remember her father said after I'd been on the 
ground a while, "I'm glad to see Art isn't always that color." 

It was a small wedding? 

Her father had had a heart attack not long before that so they 
decided to have the wedding in their garden- -they had a nice 
garden. It was a simple wedding. I could show you the video. 

Oh! Really? 

Well, Charlie had his movie camera and he took some pictures. 
I got some copies made on video lately. They didn't do a good 
job. Everything looks very blue, but still--we do, yes we have 
a little video. Not in very great detail, no sound. 

And so from your side, you had your mother and your sister? 

No, just my mother came down. 

Not your father? 


They couldn't afford to? 

I don't know why. I think maybe my parents thought he seemed 
rather foreign. He still had some kind of a strange accent-- 
doesn't seem like a Russian accent or anything else, but he had 
an accent. I think that was it, but I don't know. 

You mean that was the way he felt about himself? 

I think probably. We just sort of didn't discuss it. 

And by that time my sister was married and had at least one 
little child, so it would have been hard for her to come. 

She was living up there? 
Yes, in Toronto. 


Theoretical Work, and Publishing on Hyperfine Structure 
[Interview 3: September 4, 1996] it 

Schawlow: I've never been a real theorist, but strangely enough I think 
several of my best papers have been theoretical. It's a low- 
grade sort of theory. I don't do a mathematical calculation, I 
sort of look at the subject and present something differently 
with a minimum of mathematics . 

The thing I wanted to mention particularly now- -I was 
working on hyperfine structure of atomic spectra, and I was 
interested in what we could find out about atomic nuclei. So I 
read papers; you could read about all there was to know about 
the theory of nuclei in some pre-war papers. I think three of 
them were in Reviews of Modern Physics, by Hans Bethe, and each 
one was fairly long, but that's certainly far less than is 
known now. But even a simple-minded person like myself could 
get the general picture. 

So we were measuring hyperfine structures and I looked up 
the theorywell, there was a formula from Goudsmit, improved 
by Fermi and Segre, which let you calculate the nuclear 
magnetic moment from the hyperfine spinnings. Now magnetic 
moments were beginning to be measured at that time using 
nuclear resonance, and so I thought it would be interesting to 
compare them. And I found that one had to take into account 
for heavy atoms the finite size of the nucleus, because the 
electron wasn't just being pulled in all the way, it was being 
pulled in until it reached the surface of the nucleus. 

There were papers by Breit and Rosenthal in 1932 about 
hyperfine structure. And then a friend who was a student in 
applied mathematics, which is what they called theoretical 
physics in Toronto, told me about an obscure Norwegian paper 
which applied a method called perturbation of the boundary 
conditions. You couldn't use ordinary perturbation theory 
because going into the nucleus the electron experienced a huge 
change in the electric field potential, it wasn't just a small 
thing. However, you could imagine changing that radius 
slightly and perturbing it that way. So I could calculate the 
effects of the nuclear size, roughly at any rate, and we 
published this in a paper called "Electron-Nuclear Potential 
Fields from Hyperfine Structure" [Physical Review, 1949]. And 
this got a good bit of attention. 









We also did some work on isotope shift. But it was rather 
lucky for me that I'd been told about this Norwegian paper by 
E.K. Broch, because it certainly was not a journal I would ever 
look at. 

You were looking for different approaches? 
process always in doing physics? 

That's part of the 

Yes, I think so. Try and do something that hasn't been done 
before, that's what you have to do for a thesis, and in fact to 
publish, too. You have to do things in a different way or do 
something different. 

In Charles Townes's book, Making Waves, he seems to be making 
the point that since you can't know what you're going to get, 
you never can be too focused about what you want. 1 

Yes, you have to keep your eyes open and take the results of 
the experiment seriously, if you do get results. I've said 
before, probably not with you, that when you get some new 
results I immediately think of what it might mean. Maybe there 
are several hypotheses, it could be this, it could be that, and 
then you weed them out one by one. And probably most of them 
are wrong, but that's the way you make progress. 

How you weed them outthis is where you think your way through 

Yes, well, ideas have consequences and you might be able to do 
it theoretically, that this doesn't fit with something else, or 
you might suggest a new experiment that we should do, another 
test, a different test, to see whether that's right or not. 

Something that I readthe idea that there's a lot of 
literature and old experimental work in physics that people 

could work on using new knowledge, 
almost an historical physicist. 

It's as if one could be 

Schawlow: That's right. It's sort of like time travelling, almost, like 
the Connecticut Yankee in King Arthur's Court. And we did 
that. We'd go back to old issues of Physical Review or other 
journals, like the Zeitschrift fur Physik in the early 
thirties, and you'd see things they did, and how far they got, 
and with newer techniques you could do things that they 
couldn't do before. I have often thought that if I ever were 
short of ideas, I would just go back and look at old magazines 

'Charles Townes, Making Waves, American Institute of Physics, 1995, 


twenty or thirty years ago, and see things that have been 
forgotten and never followed up. And there are lots of them. 

I.I. Rabi pointed out in a book- - there ' s a book about him 
that's well, semi-autobiographical actually, written by [John] 
Rigden, but with extensive interviews with Rabi. He tells 
about his Ph.D. thesis which was a very clever way of measuring 
magnetic susceptibility. He says this was never referred to by 
anybody, never was a single reference in the literature to this 

Riess: That's interesting. That reminds me of the habit practiced by 
physicists of making journal entries. So if you're doing your 
daily journal- - 

Schawlow: Unfortunately, I've been very lazy about that. I'd rather 

think than write. In fact, I was at Bell Labs for ten years 
and I think I filled a little over one notebook, and most of 
the stuff I put in the notebook was wrong. If I actually got 
good results, it usually was something I'd just write on a 
scrap of paper. 

Riess: Are the notebooks considered to be in some way public property? 

Schawlow: No. They can be if they're released, but otherwise not. I 

guess mine are still at Bell Labs, I have never asked for them. 
They gave me one or two pages from it, but that's about all. 
They gave me a copy of one or two pages. 

The Atmosphere at Columbia. 1949 

Riess: At Columbia, when you were there, there were eight future Nobel 

Schawlow: It's now eleven. 

Riess: Eleven came out of that lab? 

Schawlow: Well, they were around the university in one capacity or 

another. Counting Townes and myself there was [Polykarp] Kusch 
and [Willis] Lamb, and let's see, Rainwater. Val Fitch was an 

Riess: Val Fitch? 

Schawlow: Yes. He's at Princeton. I didn't meet him then, but he was 
there as an undergraduate student. 


[Hideki] Yukawa, who got his Nobel Prize a few months after 
I arrived; he got it in October and I arrived in September. 
And let's see, there's Aage Bohr, the son of Niels Bohr. 

The most recent onesno, the second most recent ones were 
Mel Schwartz and Jack Steinberger and Leon Lederman. Lederman 
was an assistant professor at the time. Then Martin Perl got 
the prize just two years or so ago. He was a graduate student 
at the time. 

I don't know if I've thought of all eleven or not, but--. 
Well, it was really an exciting place. And physics wasn't so 
diffuse as it is now. Well, they sort of concentrated. It was 
kind of nuclear physics, and atomic physics details were the 
frontier. People could still talk to each other and they did. 
We would meet in the afternoon for tea and discuss physics 

Riess: That generosity of time and sharing is unusual? 

Schawlow: Yes, I think so, the fact that they could share, that they knew 
enough of each other's field that they could trade ideas. 

And then Rabi had great enthusiasm. He was considered a 
tough man to do research for because he really wouldn't bother 
about the details of an experiment. Two students were working 
on a problem he proposed, and after working for a year or more 
they decided that it just could not be done with that sort of 
apparatus. When they told him, he said, "Well, I'm sorry," and 
they just had to find something else to do. And they did, but 
that ' s sort of the way he was . 

But he had great enthusiasm. I remember he went to Japan 
for a couple of months, a few months after I came there, and 
when he came back he came around and poked his head in the door 
of my lab and said, "Well, what have you discovered?" Gee, 
the thought that I might discover anything somehow really 
hadn't hit me. I think maybe "finding out something," but--. 
It was inspiring. 

Riess: So he really put his imprint on the department. 

Schawlow: Yes, and he had hired a lot of people. He hired Charlie. He 
heard him speak, I think, at an American Physical Society 
meeting and he lured him away from Bell Labs. 

Riess: Then he got Charlie working on the microwave spectroscopy? 

Schawlow: Well, Charlie was working on microwave spectroscopy at Bell 
Labs. He started it. He didn't stay there because although 




they were happy to have him work on it they wouldn't give him 
any assistants, so he had to pretty much do it by himself with 
occasional collaboration from other physicists there. And he 
had a lot of ideas and wanted to have a group, so that's why he 
came to Columbia, at least as far as I know. He did build up a 
group rather rapidly. 

I had the same feeling myself when I was forty and started 
getting offers. I had a lot of ideas at that time, and I just 
couldn't do them all. I didn't even ask because Bell Labs 
didn't, at that time, have people working in groups. So when I 
came to Stanford I got a lot of graduate students and we could 
try a lot of different things. 

Back to Rabi's comment, what is the difference between an idea 
and a discovery? 

Well, I guess I think of a discovery as being something 
important. [laughs] Discovering, rather than finding out. I 
don't think it [the comment] changed what I did, but it was 
sort of inspiring just the same. 

Publications and Timing 

Riess: One of the things I'm gathering from what you're saying is that 
a lot of papers get written before the actual work is done. 

Schawlow: Yes. I don't know whether Charlie told this story or not. 

Schawlow: Charlie didn't publish the idea of the maser before it actually 
worked, and the reason was that in the years after the war a 
lot of people were rebuilding labs or building new ones, and 
they did write a lot papers proposing various experiments. 
People joked that we should call Physical Review "Physical 
Previews . " 

So by 1951 when he got the idea of the maser it was sort of 
Just not done to publish a possibility, you should go ahead and 
do it. That's the way he did. He wasn't secretive. He didn't 
formally publish it, he put it in his progress reports which 
were unclassified and were in some libraries. 

He might not have gotten the Nobel Prize- -because you have 
to publish for thatexcept that he went to Japan and he gave a 
talk and Koichi Shimoda wrote it down and published it. So he 


got a publication there on the idea of the maser. Because 
about that time, Basov and Prokorov in Russia published part of 
the idea. They didn't have anything he didn't have. He had 
more, actually, but they did publish part of the idea and they 
shared the prize in 1964. 

Riess: But the witnessed journal entry, doesn't that count? 

Schawlow: No, for patent purposes that's fine. For publication credit, 

no, it doesn't work. You have to publish, to get a Nobel Prize 
at least, and I think for most other physics prizes. You have 
to put your name on something, and often it's hard to decide 
when you really are confident enough in a result that you will 
publish it. 

There's a story about the discovery of what was it? The W- 
boson? The thing that Rubia got the Nobel Prize for. There 
was another group at CERN, that is the European Nuclear 
Research Center, that was working on the same project, looking 
for this particle, and knew just what they were looking for. 
Well, he met the leader of this group in the hall one night and 
said, "We must be cautious, be careful not to publish 
prematurely, because we could be wrong." And at that time he 
had a courier on the way to Amsterdam with a manuscript for 
Physical [laughter] That's a little dirtier than one usually 
does, but that's the way high energy physics is. 

Riess: I'm surprised that there's not more of it. 

This is different from the Rabi and the afternoon tea party 
kind of physics. 

Schawlow: You keep looking for new ideas and new ways to do things. 

Riess: If you talk about new ideas, people might say to you, "Well 
that just can't be done," and you can't listen to that, can 

Schawlow: No, you have to decide for yourself. Of course, there is the 
famous example of Rabi trying to talk Charlie Townes out of 
working on the maser. I think he argued that it wouldn't work 
and he should give it up, but Charlie had done the analysis 
himself and he felt confident, and he was right, of course. I 
usually haven't worried too much about that. 

There was one case where a theoretical physicist talked us 
out of doing an experiment, but it wasn't really me, it was a 
post-doc working in my lab that was going to try and do 
something and this theorist was visiting and persuaded him that 


it wasn't going to work, which was wrong, 
did it. 

And so somebody else 

Riess: Do you think too much energy goes into naysaying? 

Schawlow: Some people do, I usually avoid those people. 

Riess: Some people do a lot of naysaying, you mean? 

Schawlow: Yes, I think so. 

I tend to try to believe everything, but check it out. 
Even crazy things, you know, if they are excitinglike cold 
fusion for instance. You look at it at first and see, well, 
what does that imply; after a while you decide that couldn't 
be, at least not the way they described it. But I do know 
people who immediately have a negative attitude. They know 
what they know so well that they really can't fit in new ideas, 
And they're not very productive. 

Seminars and Group Meetings 

Riess: Were you the only post-doc when you were there? 

Schawlow: No, there were two others. My predecessor as the first Carbon 
and Carbide Fellow was Jan Loubser. He was a South African who 
had obtained his Ph.D. at Oxford and he was there for a few 
overlapping months. Then there was a Norwegian chemist named 
Eilif Amble. Those were the only two in Townes' group at that 

There were a number of young people around. There was this 
young Bohr, who I don't think had a Ph.D. at that time because 
the Danish Ph.D., like some other Europeans, really requires a 
lot of publications. It's not just one publication, like you 
need for an American Ph.D. And he really knew far more than 
almost anybody else, and he was a great pleasure to talk with. 
We had some interesting discussions. 

I remember once there was a seminar and John von Neumann 
from the Princeton Institute for Advanced Study came and talked 
about the theory of turbulence, which is a very difficult 
subject. Bohr seemed to understand it very well; I don't think 
anybody else did. He was running the theoretical seminars and 
he asked me to talk about what I had done on this theoretical 
work on nuclear size measurements from hyperfine structure. 
Well, I foolishly agreed. 






When I got in there, God, there was Rabi, Yukawa I think, 
and of course Townes, Willis Lamb, and Norman Kroll--a whole 
line of theorists. Well, I knew what I knew, and I didn't know 
any more than that. So 1 said something, and if somebody asked 
a question I'd pause, and usually the person next to him would 
answer it. But afterwards, one of the other graduate students 
said, "Boy, you were really shaking!" [chuckle] I was. 

Theoretical seminars were built into the program? 

For the whole department, actually. They had the colloquium, 
which would address everybody, but they would have the topics 
in the frontiers of theoretical physics. And they would have 
small audiences; maybe thirty people or so would come to those, 
whereas a couple hundred might attend the colloquium. 

But that wouldn't be a place where people would come and talk 
about ideas they were working on? 

Yes, they would be. 

Or something they had just done, their new 

Having come from Toronto, what did you learn about methodology 
when you got to Columbia that was different? 

Schawlow: Well, let's see. It wasn't really qualitatively different. I 
was able to work longer hours because I lived right near there 
and had no family. 

My lab was next to the molecular beam lab. In fact, right 
next door was Alan Herman, who later became chief of research 
for the Naval Research Lab. We would oftenmost of them would 
start work at noon and work until midnight quite regularly, so 
I kind of got into working those hours too. I'd work long 
hours, do a lot of chatting. 

It was amusingwhen I went to Bell Labs I noticed a big 
contrast. It was 8:15 to 5:15, and there wasn't much fooling 
around. There was a pause for afternoon tea for the small 
solid state physics group, but otherwise people were working 
hard all the time. You can do things in different ways. I was 
impressed by the graduate seminars, the group meetings 

Riess: The theoretical seminars? 
Schawlow: Well, those too. 
Riess: At Columbia? 


Schawlow: At Columbia. They had group meetings where different students 
would discuss what they were doing, or some particular aspect 
that they'd been asked to look into, some new development. We 
did that at Toronto too, so it wasn't really all that 
different. I think the level was higher, there were perhaps 
better students. 

Looking for OH 

Riess: Were you at all tempted to go off in other directions in that 
new arena? 

Schawlow: Not really. There wasn't much opportunity. Unfortunately I 
got tangled up in a difficult experiment which I never did 
finish. Charlie had me, in the last six months or so, work 
with some others so I'd get some publications done. I was 
working on trying to find the spectrum of the OH radical, that 
is, a fragment of a molecule. He was interested in looking for 
it for astronomy, and indeed the OH radical was found much 
later on and in astronomy it's quite important in studying 
nebulae. I was a little out of my depth there, but it's 
interesting, that was where he was interested in at that time, 
and that's why he put me on it. 

Riess: I cannot imagine the patience involved in working on something 
where it might take years before you see the thing you're 
looking for. 

Schawlow: There's a lot of drudgery in experimental physics. You have to 
get pumps and electronic equipment and everything working. You 
try and fix one thing and then another, and well--. So we 
didn't work as consistently as people at Bell Labs did. We'd 
spend a good bit of time chatting with other students. That 
was interesting, you learned some things that way, but--. 

Riess: The results Mike Sanders got were a fluke? [See pp. 75-76] 

Schawlow: Yes. Whatever it was happened to the discharge, I guess maybe 
you had to adjust the pressure of the water vapor. 

Well, we tried all kinds of things to try and get the 
result. We tried looking at the chlorine dioxide, which is 
another radical, but that spectrum was extremely complicated, 
we couldn't make anything out of it. We saw lots of lines, but 
not the OH line. It's frustrating, it certainly is. But- -I 
don't know, you keep trying to get ideas to try this, try that. 


I don't remember all the things we tried, but they didn't 
work-- [laughs] at least they didn't get the desired result. 

As I say, we spent some time looking at chlorine dioxide, 
trying to get the quadropole coupling of chlorine isotopes. So 
that took some time, and we sort of had results in that we saw 
a lot of lines, but we didn't really because we couldn't 
decipher them, there were so many lines. 

Riess: Were you counting the lines or did you have equipment that 
could do it for you? 

Schawlow: We had a scanner. There was a dial on the power supply knob 
that was connected to a clock motor and slowly turned the 
thing. And you had a chart recorder that showed the intensity 
of the signal. You should get a change when you go through the 
right wavelength, the right frequency for that particular 

There was one amusing incident. Another graduate student 
worked with us briefly when he was just starting out, named 
Wilton Hardy, and we came back one day and he had chart paper 
all around the room. He had hundreds of lines. But it turned 
out that what happened was that the clutch on the motor was 
slipping and was just drifting back and forth across the same 

Riess: Do you have to be taking notes when you're doing this kind of 

Schawlow: No. Not really. 

Riess: In order to know what you've eliminated? 

Schawlow: No, I think we just know what doesn't work. You preparedit 
took a lot of time to try each thing. You didn't just go in 
there and do something. You might work for weeks to get ready 
for this particular variant of the experiment. 

Riess: When you were talking about your own dexterity 

Schawlow: I haven't got any. [laughs] 

Riess: --you told how you were able to tune the one-tube radio. 

Schawlow: That's one thing I've learned. I'll show you here how I do it. 
[moves over to hi-fi equipment] I'd put my thumb and finger 
here and I'd push them against each other and make the fine 

Riess: But dexterity is not needed for setting up these experiments. 

Schawlow: We were looking for something on the chart recorder that was 
reproducible- - 

Riess: It can't be dependent on-- 

Schawlow: It wasn't dependent on dexterity, not at all. 


I might mention here that Gerhard Dieke, who was the head 
of the physics department at Johns Hopkins University around 
1960, told me that R.W. Wood, who was his older colleague and 
was a very famous man for his beautiful experiments, was so 
clumsy in the laboratory that he had to design these things 
cleverly enough so even he could run them. [laughter] 

Riess: Have you other stories of the Columbia years? 

Schawlow: One story. They allowed me to join the faculty club there, and 
to eat lunch there, and since I didn't have any other place to 
eat I did eat there very often. At that time they didn't have 
a lot of post-docs, there were only one or two others in the 
department, so they didn't mind me sitting there with the 
professors, and that was very interesting, to hear some of 
these discussions. 

[laughs] I may have recounted in the introduction to 
Charlie's oral history, about the time they were discussing 
this magazine article about the top young scientists. 1 

'"Another occasion, when I was at lunch in the Columbia Faculty Club 
with Charles and a few of his colleagues, the discussion turned to two 
articles which had just appeared in Fortune magazine. The science editor, 
Francis Bello, had picked ten outstanding scientists under age forty in 
universities, and ten in industry, and had tried to draw conclusions about 
what they had in common. One thing he noted was that they were all oldest 
sons or only sons. Charles remarked that it didn't seem right for him, for 
he had an older brother and two older sisters. Thereupon Rabi squelched 
him by saying, 'You didn't make the list, did you?' There can't have been 
many lists since then of the outstanding scientists of the twentieth 
century that failed to include Charles Townes." [From Arthur L. Schawlow 's 
introduction to Charles Hard Townes, A Life in Physics, ibid.] 


The Subject of Equipment 

Riess: Now, Columbia had a radiation lab group in the physics 
department. Were you a member of that? 

Schawlow: Yes. It had been a microwave lab during the war and they had 
developed what was known as the rising sun magnetron there. 
And they still had a group working on magnetrons, trying to get 
shorter wave lengthsmillimeter waves. That was one of the 
things that attracted Dr. Schulz of the Carbide and Carbon 
Chemical Company to Columbia. That was two floors; the tenth 
and eleventh floor were radiation lab. And they had an 
administrative office that handled contracts and things like 
that. They had a workshop and an electronic shop too. 

I was on the tenth floor most of the time, that's where my 
lab was. But I would go up there, I guess to order something 
or to get something made in the machine shop. There was a lot 
of equipment around there, a lot of microwave equipment. That 
was different from Toronto. There was all sorts of --waveguide 
and klystron tubes which were war surplus stuff that Charlie 
had acquired, and others I guess there. Willis Lamb also had 
experiments in the radiation lab. 

Riess: Sounds like it's important to associate yourself with wherever 
there's money so you can get equipment. 

Schawlow: I suppose so. There were strange things thereas I say, we 
really lacked a spectrograph which I needed, optical 
spectrograph. And when I came to Bell Labs it was sort of a 
shock again, because although they had huge amounts of 
equipment, they didn't have what I needed, they didn't have 
equipment for what I was going to do. Whereas at Columbia, I'd 
gone in there and it was suggested that I work on microwave 
experiments to detect OH, and they had a lot of wave guide 

They didn't have anything for what I was going to do at 
Bell, and they also had this very strange regulation that you 
couldn't buy any new capital equipment unless you could junk 
some old equipment. And of course being new, I didn't have any 
old equipment to junk. I had to hope somebody else in the 
department did. The excuse for that was Bell Labs was set up 
as a nonprofit corporation, and if they increased their capital 
by acquiring more equipment, then that was the equivalent to 
making a profit. 

Now after I'd been there about five yearswell, to show 
how bad it was, you couldn't even buy an oscilloscope. You 


could buy a thousand dollars worth of platinum and throw it 
away tomorrow, but not a three hundred dollar oscilloscope. I 
felt quite frustrated by that. After I'd been there about five 
years they suddenly realized that they could buy new equipment 
if they say it's not for general use but for a particular 
experiment. All of a sudden the purse opened and you saw big 
Varian magnets sprouting all over the place and all sorts of 
big equipment. I saw that my productivity shot up and so did 
everybody else's. Management realized that. We hadn't 
realized how much time we were spending working around the 
limitations of equipment. 

Riess: That's very interesting. 

You've mentioned Schulz and we've talked about him before, 
but this reference to his memo in August 1945 about induced 
resonance, is that like he was having an idea of a maser? 

Schawlow: No, he didn't have any idea of a maser. It was not induced 
resonance. I think it was that you could control chemical 
reactions somehow by using some radiation longer than visible 
radiation. Photochemistry is well known, it goes on every day 
in camera film, when light falls a chemical reaction takes 
place. And there lots of other reactionsbleaching, for 

But his idea was that you might be able to control chemical 
reactions if you had some radiation in between microwaves and 
visible, so that was why he supported the Columbia Radiation 
Lab. He knew they had the magnetron work, so they were 
producing shorter wavelengths, and he knew that Charles Townes 
was working on interaction between microwaves and molecules. 
But he didn't have any ideas as to how to go about that. As a 
matter of fact, the way things have worked out, the possibility 
of chemical reactions was in our minds when we were working on 
the idea of a laser. Although it wasn't really an important 
motivation, it was something we hadn't forgotten. 

Infrared has not been useful for chemical reactions as far 
as I can find out. You irradiate them but then they tend to 
quench too rapidly, they don't hold the excitation long enough 
to undergo a reaction. Also, the radiation is masked by the 
thermal radiation which is present all the time and is in the 
infrared even at room temperature. So that hasn't really 
worked out. 

Riess: Charlie is still interested in the infrared. 

Schawlow: Oh, yes. He's interested in the infrared for astronomy, but I 
don't think he's ever done anything on photochemistry, not as 


far as I know. We did for a while, and we'll come to that, at 
Stanford, but we used visible light and it wasn't very 
successful. There are a lot of things I didn't know. 

Nepotism Issues Motivates a Job Search 

Schawlow: Columbia had very strong anti-nepotism rules at that time. And 
if I was going to marry Charlie's sister, then that would be 
nepotism. There was never any possibility of staying on at 
Columbia in a permanent way at all, or even probably not at 
all. The second year, 1950-51--the Carbide and Carbon 
fellowship was only good for one year, and Ned Nethercot came 
in from Michigan and took over that. 

Charlie wanted me to stay on to help him write this book on 
microwave spectroscopy and he found some money from the Ernest 
Kempton Adams fund at Columbia University to pay my salary, 
same as I'd been getting on the fellowship, I think. But it 
meant that it was a busy time. I was still trying to get 
somewhere with this research, and he did have me work with 
other students so I would have a variety of experiences and get 
some publications. 

It was a pleasant time. As I think I said last time, I had 
started looking around, thinking that I might like to find a 
wife. And then, of course, Aurelia came around and I was in 
the mood. Well, she was very attractive. She was pretty, but 
the main thing about it was she was intelligent and, well, the 
kind of person I'd like to live with. That was really the most 
important thing for me. I never had bothered with girls at all 
before that. I just felt I couldn't afford to, either the 
money or the time. As I say, I did look around a bit, but I 
didn't see anybody I really wanted before that. 

So we began seeing each other in the fall of 1950, and I 
think in January we became engaged and married in May. 


Schawlow: It was a busy year. I did get a letter from Professor Henry 
Ireton, who was sort of the administrative director of the 
physics department at Toronto, asking if I'd be interested- -no, 
I'd gotten that before that year started- -whether I'd be 
interested in going back there as an assistant professor, but 
I'd already promised Charlie that I would stay so I didn't get 
that job. 



Then when I started looking for jobs in the spring, there 
weren't many. Whereas in '49 there'd been a great scarcity of 
people, in '51 there didn't seem to be academic jobs. There 
was the complication that Aurelia had come to New York to study 
singing with a teacher, Yves Tinayre, and she didn't want to 
leave the New York area, so that limited things. I think I 
wrote to a couple of universities but I didn't find anything. 

Then Bell Labs had a very good, efficient recruiting 
scheme. Sidney Millman, who had been one of Rabi's students, I 
think, was then department head at Bell Labs, and was 
recruiting. He'd come and talk with the professors, ask who 
might be a good prospect. Somehow he suggested me. 

I still wanted to do some real physics, so I was really 
rather afraid that I'd just get into some kind of routine 
engineering development. But what they offered me was to work 
with John Bardeen, to do experiments. Bardeen had already 
invented the transistor, or had been co-inventor, and had 
published a lot of theoretical papers. He was a theorist and 
he was beginning to get interested in superconductivity, so 
they wanted somebody to do experiments on it, and they hired me 
for that, even though I had no background in low temperatures 
or solid state physics at all. 

Now maybe that's what scared him away, but by the time I 
arrived in September, he had gone, decided to go to the 
University of Illinois. So there I was. And they didn't tell 
me not to work on superconductivity, but I had to learn about 
it and try and find something to do- -which was rather 

You were married in May? 

Yes, that's right. May 19th. 

And you were down in Washington with Charlie at the same time? 

Yes, earlier, the end of April. So it was just a couple of 
weeks before I was to get married. Two or three weeks. Maybe 
my memory isn't so good at those things. I honestly do not 
remember the incident that he ' s so fond of telling about how we 
shared a room. [laughter] It's plausible, because indeed I had 
been used to sleeping late, working this noon to midnight 
shift. So it's possible that he woke up early and went 

I don't remember sharing a room with him, but I can't 
really deny it--but I just can't confirm it either. I never 
heard about that until 1959, just before the first Quantum 


Electronics Conference. He held a party in New York for the 
various people coming to that conference including the two 
Russians, Basov and Prokorov. That's when I first heard that 
story about the park bench. 

Riess: But you did witness his notes? 

Schawlow: Yes, I did witness his notes. I'd forgotten that too, so I'm a 
real forgetter. [laughter] I remembered him telling me about 
the idea. What I didn't remember particularly was signing his 

Riess: Do you remember the electricity in the air? 

Schawlow: It was an interesting idea, I thought, yes. You couldn't be 
sure it would work, or how difficult it would be to make it 
work, or how useful it would be. But if I hadn't been going to 
Bell Labs, I would 've liked to work on that. That would have 
been a good project. 

Riess: Well that's really what I was thinking about. I never have 
heard of nepotism that has to do with the wife being-- 

Schawlow: --the relative. Well, Charlie is a very upright person, very 
correct, and I think he pointed that out to me. 

At the time I didn't feel I was good enough for Columbia, 
to tell the truth. I didn't have as strong a theoretical 
grounding as I should have had, so I wasn't too concerned about 
that. I think now that I probably could have stayed on there, 

When I was talking about staying the second year, Polykarp 
Kusch was the chairman, and he came around and asked me if I'd 
like to be an assistant professor. That would be in 1950, 
before the 1950-51 academic year started. And I had to say 
that I really couldn't see how I could manage to do research 
and write on the book and still do some teaching. Well, he did 
offer me that, if I wanted it, and he might have offered me 
something in 1951 too, but--. 

More on Writing the Microwave Book 

Riess: We will get you to Bell Labs, but this business of writing that 
book-- . 

Schawlow: Ooh, horrible job. 

Riess: You tell me why it's a horrible job. 

Schawlow: To begin with, 1 didn't know anything much about microwave 

spectroscopy. I'd only worked on it really for a year. Well, 
we divided up different chapters, and I had to draft some of 
the chapters and Charlie drafted the others . All the more 
complicated things he did, and the things I did he revised 
pretty heavily. But it was a lot of learning. I had to read a 
lot of papers and try and boil it down into understandable 
prose. We were writing about basic principles, and also 
reporting on what had been done. 

I felt when we started on it that if I was going to do it 
at all, I really want it to be a classic. And I think it is. 
It's still in print and has been referred to many, many times. 
So I was willing to dig fairly deeply in the stuff. There was 
a review of the basic theory: you had to do molecular theory 
and microwave theory, and I think we even had a chapter on 
atomic physics to bring the thing up to the start. Then a lot 
of the detailsCharlie did a lot of detailed stuff on the 
interaction of microwaves with molecules, and that can get very 
complicated, particularly if you get asymmetric top molecules 
that have little symmetry. 

Of course, my attitude about molecular spectroscopy up 
until then was given by a definition that I've repeated many 
times: that a diatomic molecule is one with one atom too many. 
[laughs] It can get very complicated, and here they were 
dealing with atoms that actually had even more than two atoms. 
So I had to read a lot of theory and try and put it in 
understandable form. 

After I think about eleven chapters or so on the 
spectraand they would be illustrated by reports of 
experiments that had measured certain things there--. The 
bibliography had a thousand and one references. Actually, it 
was a little over that, but we put in some "a's" and "b's" so 
we'd come out a thousand and one. 

Then after that there were several chapters on microwave 
techniques and one on millimeter waves--! remember I drafted 
that one. Of course, millimeter waves were not very advanced 
at that time. They were beginning to be used, but I remember I 
started the thing off saying something about their difficulties 
but techniques nevertheless are now available. And there was a 
misprint in the book, and it came out that "techniques are not 
available." The editor from the publisher said they expect 
about one error per page on a technical book like that, and we 
had the manuscript read by several graduate students and still 
there was about one error per page. 








Maybe they were just predisposed to thinking they were not 

Well, anyway, that's the kind of thing where Spellchecker won't 

I once put a speech synthesizer in my computer that would 
read text that you have in there. And I caught a mistake 
there. I think I had and "of" instead of an "or." I haven't 
done it since then, but it seemed like a useful idea. 

Did you have any trouble with the writing? 
write in general? 

Do you struggle to 

Yes, I do struggle. I used to think I could write pretty fast, 
but I couldn't. And when I do a draft or something I tend to 
cross about every second or third word and keep struggling with 
it. Usually, though, when I'm through the first draft, I'm 
through, because I've done my revisions as I go along. I guess 
now I'm probably doing a little more revising, but generally 
the first draft is a struggle. 

For the spectroscopy book, did you write it by hand? 

Yes. It was all by hand. I did have a typewriter at the time, 
but I think Charlie's secretary did the typing, I don't 
remember typing any of that. Of course, there were a lot of 
mathematical symbols. 

I remember one thing is that when I was a student the 
people teaching electricity and magnetism used the centimeter, 
gram, second system of units--cgs, those were the basic units. 
But the engineers foisted on us the mks system, which is meter, 
kilogram, second. Let's see, now, we wrote the chapter on 
microwave techniques first I think in mks. Then we decided 
that physicists were more comfortable with cgs. And then we 
were persuaded to go back again and translate it back, which 
was a certain amount of bother. [laughs] I think we ended up 
with the mks system. The engineers were the ones who pushed 
the mks, but the physicists had given up on thatmostly, not 

Who were you writing the book for? 

McGraw Hill. 

For the engineers or the physicists? 

Well, physicists and chemists mostly. The mks system had been 
accepted by national standards bodies, and we were told it was 





Riess : 



supposed to be the system of the future. We wanted to be 
understandable, so that's the way we ended up. 

Well, all things considered, 1951 was a big year. You decided 
to stay and work on the book, not to go back to Toronto, for 
instance. And you are very identified with the book? 

Well, clearly Charlie is the senior author on that, and he's 
gotten at least one award for it, but yes, it helped me a lot, 
helped my reputation quite a bit, because it is a formidable 
book even though I didn't write it all. But for me personally 
it was a waste of time, because I haven't worked on microwave 
spectroscopy since then. I practically never looked at the 
thing again but it was good advertising. 

You were working on that when you were at Bell Labs. 

Yes, it went on and on. I would go in practically every 
Saturday to Charlie's office to work on it. I guess I worked 
on it some at night too. I finished it I think in '54. It 
takes some months to actually get it into print, but it came 
out around June of '55, May or June. 

Not an ideal way to start out being married, 
much more like a graduate student. 

That's living 

Yes, it wasn't an ideal way to start a career at Bell Labs 
either. It was distracting. I could 've done better. You 
know, we managed. Aurelia was understanding. I didn't do much 
writing at night, actually. It was mostly just Saturdays I 
would spend on it. 

Oh, we had tickets for chamber music concerts in New York, 
and quite a few Saturdays I would go into New York in the 
morning, and come back home at around noon or so, and then go 
into New York for the concert in the evening. I remember being 
rather sleepy during chamber music concerts. 

Did you pursue your interest in jazz or did marriage end that? 

Well, kind of dampened it a bit. I didn't really pursue it 
seriously at that time. There was a hiatus for a few years. I 
picked it up again when we came west and I had more room to 
store records. 



Experiments on Superconducting Phenomena 

Riess: Let's talk about your work in superconductivity at Bell Labs. 

Schawlow: Well, I did some cute things. They didn't solve the problem of 
superconductivity. Bardeen, Cooper, and Schrieffer did. 

Riess: Were you the point man on superconductivity at Bell Labs? 

Schawlow: Superconducting phenomena. I should explain that Bell Labs 
seemed to want to cover a lot of fields. They said that the 
purpose of research there was so that they would be informed 
about the latest developments that might affect their 
technology, and they felt the best way to do that was to have 
people working in the different fields. It wouldn't do any 
good to have somebody sitting in the library and reading stuff 
because that would be a year old. But they wanted people to go 
to meetings and discuss on an equal level with others in the 
field so that they would really know what was going on in the 

I was the only one working on superconducting phenomena. 
Bernd Matthias was working on superconductive materials. He 
was sort of an alchemist. He mixed together all sorts of 
things, worked very intuitively, and he did find some new 
superconducting materials, and ferro electric materials too. 

Hal Lewis did some work on the theory of superconducting 
phenomena. I had the feeling about superconductivity that it 
was such a perfect thing that it was awfully hard to get a 
handle on it. I mean, the electrical resistance is really 
zero, not just nearly zero. Magnetic fields just don't 
penetrate. Well, we did do experiments where it had been found 
that magnetic fields do penetrate a small distance sometimes, 


something like a few hundred to a few thousand angstrom units, 
an angstrom being 10~ 8 centimeters. Oh, I'm showing my age: it's 
10' 10 meters. In fact, you're not supposed to use those units 
any more. You're supposed to use nanometers, a nanometer being 
ten angstrom. 

Anyway, that's a small distance. But one of the 
experiments I did was to measure the penetration depth by 
winding a coil very closely around a rod of superconducting 
tin. And you can get very pure tin, it was surprising. You 
could buy it from a company called Vulcan Detinning. It turns 
out that people do recover the tin from tin cans. And there's 
not much on a tin can, so they have to have extremely selective 
processes which take the tin and nothing else. So you can get 
tin that's extremely pure, and so we got some and made up a rod 
of it. We wrapped a wire coil very closely around it. In fact 
we wrapped it around the inside of a glass tube. I used to kid 
people, say that I did it by a simple application of 
centrifugal force, but in fact we had it wound first. 

Bell Labs facilities were very useful there. We got 
niobium wire enameled, coated with Formvar, which is something 
you couldn't buy on the market but they prepared it for us. 
Then they wound it on a mandrel, on a rod, and it was just the 
right diameter. Then it would be cemented together with this 
Formvar. Or rather, they'd put some kind of cement on it and 
slip it inside a glass tube and then remove the mandrel. Then 
you put the tin rod in place of where the mandrel had been. It 
was a close fit. 

What we did was to measure the inductance of a coil which 
depended on the amount of magnetic flux inside it. Well, 
magnetic flux depends on the magnetic field and on how much 
space there is. And the volume was small, just the space 
between the rod and the coil, and whatever penetration distance 
there was. So what we could do was measure the change in the 
penetration depth as it cooled it through the superconducting 
transition. We did that by making this coil part of a radio 
frequency oscillator, and then the frequency of the oscillator 
would change, and we had a crude frequency counter which were 
just becoming available, and we could measure the change in 

It turned out that--. This was not the first thing I did, 
it was more like 1957 I think. But we found a departure from 
the predicted dependence on temperature. The penetration depth 
fell out more rapidly as we cooled it. These were small 
effects, but we were able to measure that the penetration depth 
changed more rapidly than the simple theories had predicted. 
And it turned out that this was also a prediction of the 


Bardeen, Cooper, Schrieffer theory which came out about the 
same time. Bardeen asked me to present these results at a 
conference that he was organizing. And so that was useful. It 
helped to confirm the BCS theory, but it didn't really open any 

We did another experiment earlier where we used penetration 
through a thin film, and there I really missed something. What 
we did was have a thin film coated on the inside of a glass 
tube, and then put a tiny little coil inside it to pick up what 
signal could get throughwe'd have another coil outside with 
an audio frequency signal and pick up the signal and measure 
how much it was . 

We got some results which were reasonably consistent with 
other measurements of penetration depth, but we noticed that 
there were spikes sometimes coming through suddenly. Hal Lewis 
suggested that maybe it was flux quantization, which would have 
been a great thing to discover. But we didn't take it 
seriously. We thought it was associated with defects in the 
film because you got it some places, not others. But that's 
exactly what we should have expected would permit flux quanta 
to penetrate through. So we could have discovered quantization 
of magnetic flux in superconductors, but missed it. 

Riess: How big a deal would that have been? Is that something 
somebody discovered later and got a big Nobel Prize for? 

Schawlow: Well, unfortunately not a Nobel Prize. My colleague at 

Stanford, William Fairbank, discovered it about the same time 
that I came, in a different way. He should have had a Nobel 
Prize for it, but it was discovered independently in Germany by 
R. Doll and M. Nabauer, and then Nabauer died a few months 
later. So I think maybe that's why they didn't give a Nobel 
Prize for that. I think he should have had it, I nominated him 
for it. 

The reason why it was interesting was because the flux 
quantum was only half of the value that people had predicted. 
The value was hc/2e. That is, it depended on two electron 
charges--h, Plancks constant, divided by 2 times the electron 
charge. Now the reason that is important is because the 
Bardeen, Cooper, Schrieffer theory depended on pairing of 
electrons. So pairs of electrons get coupled together and 
provide the superconducting current. 

That could have been an important thing. Now, wait a 
minute, the BCS theory was already there, not from when we did 
our experiments but when Fairbank and Deaver--who was a 
student, Bascom Deaver--discovered the flux quantization. 


Still the fact that it was hc/2e was a useful new piece of 
information. It surprised a lot of people. 

Riess: When you were working on this, who would you report to? How 
was it set up at Bell Labs? 

Schawlow: There was a department head, a man named Stanley Morgan. He 

was a chemist. He was a good administrator. He had been joint 
head of the solid state physics group with Bill [William] 
Shockley, but Shockley had been an impossible person to get 
along with. They had split the group, and Shockley had a group 
on transistors, and the rest of solid state physics was under 
Morgan. Although he was a Ph.D. physical chemist, he didn't 
really try to tell us what to do. 

I remember that one of the technicians there, quite a good 
man named Ernie Corenzwit, went to Stan Morgan one day and 
asked him when should he ask about what to do. And he said 
Morgan told him, "If you know what to do, do it. If you don't, 
ask." I thought that was a good philosophy. In fact, when we 
came to Bell Labs they had indoctrination sessions. One of the 
men there told us, "The first thing you've got to learn is 
there are no oracles. You'll have to think things out for 
yourself." So they didn't interfere much with that. 

Earlier I had done some nice work on the interface between 
superconducting and normal regions. Although it was a cute 
idea, I don't think it was really important. When a magnetic 
field penetrates into a slab of superconductor, if the field is 
perpendicular to the slab, then it comes in in regions. And 
some regions are normal where the magnetic field has penetrated 
and destroyed the superconductivity. And the regions in 
between them remain superconducting. This is known as the 
intermediate state. There's been a lot of speculation about 
that and you could measure the surface energy of these 

Well, what we did was to sprinkle niobium powder on the tin 
plate and photograph it. Niobium powder is superconducting and 
it's pushed out of magnetic fields, unlike iron filings which 
would be pulled into a magnetic field. But the niobium powder 
is pushed out, so you saw a nice pattern of the lines of spaces 
on the thing. 

And we got several papers on that. We did it first, I 
think, with polycrystals and then we did it with single 
crystal. Then we were very surprised because the magnetic 
field penetrated faster in the direction that we thought was 
the wrong one because the higher the conductivity, the more 


dampening it would be, it would slow down the motion. But it 
came in the direction where the conductivity would be higher. 

This worried us a great deal. In fact, Bob Schrieffer was 
a graduate student, one of the people who did this, later got a 
Nobel Prize for the theory of superconductivity. He spent the 
summer there. And Hendrik Gorter from Holland was there, and 
nobody could explain it. But then I did a measurement of the 
magneto-resistance of this very pure tin and I found out that 
by the time you reach the field of a couple hundred gauss, 
which breaks down the superconductivity, the magnetoresistance 
has crossed over, and the direction which was high before 
became low. 

Your picture it like this: look at my hand here. If I put 
a magnetic field perpendicular to that, then the field would 
penetrate in there and I would see these lines. If you have a 
square plate, you couldn't tell which way it was going to come, 
it would come in from all the edges, but it comes faster in the 
direction where the resistance across here is higher because 
that doesn't dampen as much. 


Schawlow: As I say, then we did this experiment to measure the 

magnetoresistance, which is hard to because these things are 
extremely good conductors even in the normal region--this was 
very pure tin, I think it was something like a hundred thousand 
times lower resistance than at room temperature. So again, I 
did an experiment where I wrapped a coil around the thing and 
measure the inductance, and that gave me the resistance. I'm 
pretty good at putting coils around things, [laughter] 

Riess: You talked about Bernd Matthias and other people. Was this a 
team that was working together and constantly talking? 

Schawlow: No, no, absolutely not. Matthias was strictlyhe was a very 

intense sort of person, and he was extremely original. In Bell 
Labs I gather he used to wear no socks a lot of the time, was 
considered one of the wild men around there. When he would 
rehearse a talk--. They would get you to rehearse your talks 
at Bell Labs, which was very good thing. It's one reason Bell 
Labs people had a reputation for giving good talks. But he 
would be outrageous, he would say horrible things, and then 
when the actual date came he would give a good talk. But he 
just liked to put people on. 

For a time we shared a laboratory with him. Now he 
wouldn't do anything as far as the experimental equipment was 
concerned. He had collaborated with John Hulm, who was at 


Westinghouse, and Hulm had given him a design for a cryostat 
where he could test his samples. All he would do washe might 
have Corenzwit make up some samples, using electric arc melting 
usually. Then he would bring them in and lower them one by one 
into this cryostat, and check whether there was superconducting 
or not. That was in the same room that I had my apparatus, but 
it was a simple rule that when he was there, I wasn't. 

Research, Resources 


Bell Labs didn't work in teams? 

Schawlow: They didn't work in teams, not in the basic research. 

The one thing I didn't realize for a long time--. I really 
didn't make use of the resources. The way things happened at 
Bell Labs was Mr. A gets an idea; he goes to Mr. B who makes a 
sample for him; and takes it to Mr. C and D who make 
measurements; and then to Theorist E; and they come out with a 
paper with five names on it. And they say, "Oh, Bell Labs has 
put a big team on this," whereas generally by that time, 
they're not even speaking to each other. 

I didn't realize that there were a lot of lonely people, 
like myself, sitting around, and they have equipment for 
something or other. If somebody can think of what could be 
done on that equipment, they can drop what they're doing and 
help you. It was very good. Both the experimentalists and the 
theorists too would help each other when you asked them. But I 
was too shy to ask them most of the time. The last few years I 
did begin to work with others. 



How did you get from one problem to the next? 
that something was done? 

How did you know 

You read. To begin, there's a book by David Shoenberg, from 
Cambridge, on superconductivity. I read through that and 
looked for ideas, and that's where I got the idea of measuring 
penetration depths. Then, well, I talked a little bit with 
Lewis, even Matthias very occasionally would talk. In fact he 
had the idea of looking at the intermediate state by sprinkling 
iron powder on the thing, and the iron would be pulled into the 
regions where the magnetic field had penetrated. I persuaded 
him that it was better to use the superconducting powder that 
would stay away from the regions where there was a magnetic 
field. Now I'm not so sure that really was better, but it 


Riess: I'll give you a break and read some of the Bell Labs philosophy 
on doing basic research: "...[research] deals constantly with 
uncertainty, except that there is ever present the certainty 
that important new things remain to be discovered..." 1 

Schawlow: And there were not very many people in research, maybe a couple 
hundred people in the whole place out of about seven thousand 

Riess: "...[research] must assure the flow of invention and new 

science that will enable future technologies to be developed. 
And it must see the ways this invention and new science can be 
exploited by Bell System." 

Schawlow: Yes, well, maybe not right away. A lot of their research was 
more closely tuned to communication needs. 

I used to worry sometimes because I couldn't see why what I 
was doing was going to help the Bell System at all. But there 
were people doing communication research. Oh, for example, the 
satellite communication, they pioneered that, first with 
reflecting balloon satellites. Oh, they developed the 
travelling wave tube there and things like that, which were 
research but they were more directed toward the needs. But 
ours was just basic physics, not all kinds of physics, but 
physics of materials and things that were related to the kinds 
of things they did. 

But the inventions that came out of our department, I 
think- -there were few, and they didn't expect many from the 
basic research. And they were very expensive. Things like 
transistors and lasers took millions of dollars to develop 
because they were so far out before they could get any use from 

Riess: Where else was similar research going on? 

Schawlow: There was work at Columbia, and at Rutgers too. I guess we 

knew what they were doing, what they published, but it wasn't 
very close to what we were doing. About the only people doing 
things close to what I was doing were a couple guys in England 
and in Russia. Maybe I hadn't chosen very well, but it felt 
rather isolated. 

We did do one useful thing for Bell Labs which maybe paid 
for our salaries during that time. I think it was Dudley Buck 

1 xv, A History of Engineering and Science in the Bell System: 
Physical Sciences (1925-1980), AT&T Bell Laboratories, 1983. 




at MIT who invented a superconducting switch that you could 
make switching systems orcalled a cryotron. You could in 
principle make computers or even telephone switching networks 
from that. 

So they had a meeting. IBM put a lot of people on it, I 
don't know, maybe a dozen, or twenty. They tended to throw a 
lot of people at problems. They did that on ferro-electric 
memories before that, and then they sort of worked for a couple 
of years and gave it up. I'm told that Watson said, "There's 
so much money to be made in computers that we can't afford to 
overlook anything." And that was true in those days. 

So they had a meeting to ask should we at Bell Labs get 
into cryotrons. Lewis and I went there and pretty easily 
persuaded them that they shouldn't. And indeed nothing did 
come of it at that time. There were two reasons: one is that 
it had to be in liquid helium and, well, it was primitive and 
not very fast either at that time; the other thing is that 
while you might use it for computer calculations, it wasn't 
suitable for the telephone system where you're switching. You 
need a lot of input and output, so you had to have a lot of 
wires coming in and out of the low temperature region which is 
very hard to do, because they conduct heat. So anyway, we did 
tell that it wasn't worth getting into and I think saved them a 
lot of money. 

Just because one part of the word is the same, 
and semiconductors are not. 





They're worlds apart. They're both solids, but--. And I 
didn't work on semiconductors. 

Shockley would have liked me to work for him I think, but 
Charlie had warned me and so I didn't go to work for him. 
Charlie said, "He's nice, but if he thinks you're a rival, he 
can be pretty hard." I don't know whether you know his history 
here in California but he started the Shockley Semiconductor 
Lab which was financed by Beckman. And he hired some very good 
people, but then they went off and started other companies: 
first the Fairchild Semiconductor Company and then a lot of 
others, National Semiconductor and maybe Intel. He was so hard 
to get along withhe knew good people, he had high standards- 
He inspired an industry. 
Oh yes, he did, he was very important. 

Inspired it by people wanting to get as far as possible from 


There's a whole list of things that were developed while 
you were at Bell Labs. High temperature superconductivity was 
one of the things, though somewhat earlier, between 1951 and 

Schawlow: Oh, goodness. Well, high temperature is relative. Matthias 

and [T. H.) Geballe did work on some materials and I think they 
had for a while the highest temperature superconducting alloy. 
I think it was niobium germanium. It had transition 
temperature of around twenty degrees Kelvin, so you could 
actually run it in liquid hydrogen rather than liquid helium. 
But that ' s nothing like the high temperature superconductors 
that were discovered in the 1980s. They go up in temperatures 
over a hundred degrees Kelvin. They can be run in liquid air 
which makes a big difference. 

Let me be fair with them there. This materialwas it 
niobium germanium or niobium tin? one of these fairly high 
temperature superconductorscould also resist magnetic fields 
better than others, so that you could wind a magnet from it. 
Now if you wind a magnet coil from superconducting wire and put 
a current through it it produces a magnetic field, but when 
that's strong enough, it destroys the superconductivity. These 
could resist that, so these wires are still used for 
superconducting magnets which are used quite widely in magnetic 
resonance imaging devices. 

So the high temperature wires, they were important- -even 
though I wouldn't call it as high a temperature now. For those 
days it was high, and those are still the best for the magnets. 

Murray Hill and the Work Day 

Riess: Let's just get you situated a bit now. 
you were? 

Murray Hill is where 

Schawlow: Yes. It was a little town, almost nothing there except this 

huge Bell Labs laboratory at that time. I think now it's been 
built up quite a bit around there. It was out in the country 
pretty much, west of Summit, New Jersey. The nearest town was 
New Providence. There was a Murray Hill post office, I think, 
which was the largest second-class post office in the country 
or something like that because of all the Bell Labs system. 

Riess: I want to make sure that we really get an idea what is was like 
to work for the Bell Labs, what the virtues and the drawbacks 
were, and how you could ever be induced to leave. 


Schawlow: It wasn't hard. 





Charles Townes spent time trying to get them to do things that 
they were so slow to think about doing. 

I was shyer, probably. I didn't really particularly try to get 
them to do things. I could have and should have. Like, for 
instance, when we had any ideas for lasers, I should have tried 
to get them to give me some people to help me try and build 
one. They didn't have anybody, and that's the way it was, so I 
didn't try to build one. I just sort of assumed it wasn't 

I worked conscientiously, but I didn't work much at nights, 
only very rarely went in at night or on weekends . I spent a 
lot of time with my wife and then family. It was sort of like 
a job. I mean, it wasn't as consuming as it has been at the 
university. Of course, the university, you have teaching and 
administration, all added on. 

It sounds like they set it up to make it just like a job, if 
you've got to be in the parking lot at eight-- 

Eight-fifteen, yes, at the beginning. Yes, I think so. It was 
an industrial company, really. They changed that. About the 
last couple of years I was there, maybe the last three years or 
so, they decided they were going to make more spread in the 
salaries and they would have formal evaluations of people. 
They would divide them into octiles, the best eighth and so on. 
Well I don't know how my rating was, but I don't think it was 
very high because I was working alone on superconductivity, and 
no great invention had come out of that. 

At one point Hal Lewis and I asked the boss if we should 
write down some ideas. We could think of inventions, like 
switches and so on. He said, "Well, does it have to work in 
liquid helium?" I said, "Yes, I guess so." And he said, "Well 
then don't bother." So we didn't bother. 

As I say, I think they really didn't think very highly of 
me because they made me the department safety representative, 
and that's usually a kind of drudgery job that they give to 
somebody who isn't doing anything else much. About the only 
thing I did was that I had to write an accident report when one 
of the theoretical physicists stabbed himself with a pencila 
sharp pencil. I pointed out that theorists should be 
instructed on the uses of pencils [laughter]. 


Another thing you did was teach while you were there, 
taught a class on solid state physics. 



Schawlow: Yes, that's sort of ridiculous, but they asked me to do it and 
I did it. I learned solid state physics as I went along. It 
was kind of fun, but it was work. I had to go to New York for 
those [lectures], three days a week I think it was. 

Riess: You mean you were teaching in New York? 

Schawlow: The new engineers who were coming in. They still had a big 

laboratory in New York. That was their headquarters for a long 
time. People would come from Murray Hill, maybe even from 
Holmdel, which was mostly military engineering. I don't know, 
we didn't get to know who the students were very well. 

Riess: You also built an audio frequency parametric amplifier. 
Schawlow: Oh yes, just for the heck of it. 
Riess: How did that fit in? 

Schawlow: Well, after the maser came along, some people realized thatI 
think it was Harry Suhl who realized you could make what we now 
call a parametric amplifier. (I think Rudy Kompfner gave it 
the name.) It's one where you change the parameters of a 
circuit, namely the inductance or capacity. If you do that at 
twice the resonant frequency by the circuit, then you can make 
it oscillate and you can make it amplify. 

I tried to learn, get my thoughts straightened out, you 
know, how did this compare with masers, which I wasn't working 
on, but I was interested in them. It was rather simple: you 
could find in the stockroom toroidal coils, that is, with a 
doughnut-like iron core. You'd find that in the stockroom and 
then you put that in the circuit board with a capacitor, and 
you'd get a resonant circuit. Then I would change the 
inductance of that coil by wrapping another coil around 
itthese are very high permeability cores, and because of that 
they're easily saturated, you could saturate them on every half 
cycle, or so, and so you could change their inductance. We did 

It was just kind of fun to make that. I think I wrote an 
internal report on it, but I didn't publish anything on it. An 
interesting sidelight is that Suhl had invented this parametric 
amplifier that used a microwave ferrite. He didn't build it; 
he was a theorist, a very formal theorist, but he could invent 
things with formal mathematics . 

Then he realized the generality of this concept, and they 
made an application for a patent in his name, but the patent 



office came back and said, "You can't have that patent because 
Bell Labs already has a patent"--! think it was Jacobsen, I'm 
not sure, issued in the 1930s. It had just been forgotten. I 
think they didn't realize that the parametric amplifiers were 
low noise amplifiers and didn't realize the importance of that. 

This man was still around, this guy whatever his name was, 
though he was in a different department. We never met him. 

Then in 1957 you and Charles Townes got back together again and 
start doing things . That sounds like the place where we should 
begin next time. 

Madison, and Home Life 

Riess: Before we finish today, would you describe life during the Bell 
Labs period? You and Aurelia lived in Madison? 

Schawlow: We lived for the first five years of our marriage in 

Morristown, New Jersey, and then we bought a lot in Madison and 
had a house built there in 1956. We were very lucky in a way: 
there was a section of Madison, a very nice section adjacent to 
Drew University, which had been partly developed in the 1930s 
and then people ran out of money. So some lots were left in 
among the houses. We were able to get one from an old couple 
who had finally decided they were never going to be able to 
build there. It was covered with dogwood trees, lovely, a very 
pretty area--Woodclif f Drive in Madison. 

Riess: And you got an architect? 

Schawlow: Well, we got a set of plans from a magazine, you know these 
housing magazines sell plans. Then we hired an architect to 
modify it for the particular lot, adapt it to the lot. Then we 
had to get bids and they were all high. But then this black 
man came along, Reverend Sanders I think. Anyway, he was a 
minister part-time and builder. He hadn't built a house, 
actually, but he was a carpenter. He didn't do a bad job on 
the thing. 

We said we wanted to be able to put in air conditioning 
later on, and the architect hired a heating consultant to 
design the ducts for that. The builder got a heating and air 
conditioning man who took one look at those plans and said, 
"Those ducts won't go in those beams. They're too big." So he 
said, "Leave it to me, I'll do it right." So it was sort of 
architect-designed. It was a nice house, we liked it. We made 



one mistake. We didn't bother to have a garage. We didn't 
really need it, but I think when we were selling it it probably 
was a defect. 

When we came to sell it in 1961--we were moving away--we 
had quite a hard time. We tried to sell it ourselves but we 
didn't succeed. Finally got a real estate agent who sold it 
shortly after we left. But one of the big problems was that at 
that time they were talking of building a third New York 
airport in the so-called Great Swamp, which is near there and 
we would have been right on the flight path. So that depressed 
housing values at that point. 

What did you like to do? Did you do outdoorsy things at all? 

Schawlow: Not very much. We liked to go to concerts and shows, things 
like that. 

It was rather unfortunate, in a way, that Aurelia had got 
this job at the Baptist church in Morristown as choir director 
and organist. A wonderful man was the minister, Mr. Barbour. 
She had written to several churches, and one day when she was 
feeling particularly depressed he showed up at our apartment 
and offered her the job, and that really made things look up. 

She was a very good choir director. She had directed a 
choir, choruses. She'd taught music at a college in Georgia, 
Piedmont College, even put on a concert with Percy Grainger, 
the composer. He came there and they played his music--! guess 
he played some too. But what was unfortunate was that she 
didn't know how to play the organ, although she played piano, 
so she had to take organ lessons, and for the first few months 
they had a substitute organist. 

She had a good choir there. But that meant every Sunday we 
had to be at home, we couldn't go away for weekends, which was 
a limitation. And I had to work during the week. When we had 
vacations, we'd usually drive up to Toronto or down to South 
Carolina to visit folks there. 

I guess our common interests were mainly cultural, and also 
in the church, too. We got active in the church. I was on the 
board of trustees and even on the deacons --which was clearly 
ridiculous. It was a very liberal church, and although it was 
a Baptist church, you didn't have to be baptized. And I hadn't 
been, and as an adult I didn't feel like doing it. But they 
still wanted me on it. 


That's why you're saying it was clearly ridiculous. 


Schawlow: Yes. And there were young people's groups. We got some 
friends there. It was a nice time and nice people. 

Riess: Did you have your children by then? 

Schawlow: We had trouble having children. Aurelia had to have- -what is 
that test where they put carbon dioxide into the fallopian 
tubes? Apparently pretty painful. But after that we had 
children. Our first year or two, we thought better not to- -the 
advice you usually get is don't have them too soon. But then 
afterwards we were trying and not getting anywhere. So finally 
we took that test and then Artie was born in 1956, Helen in 
'57, and then Edith in '59. They were all born during those 

Riess: But for the first year she was in the apartment and depressed 
and happy to be offered the job. Why depressed? 

Schawlow: That was just shortly after we came to Morristown. We went to 
a garden apartment complex there and they had thin walls . She 
wanted to practice, and there was a woman I think downstairs 
who absolutely would not allow her to practice anytime. 
Aurelia tried to arrange a time when she could do it and just 
wouldn't. We fortunately found another place which was the 
second floor of a house on the other side of Morristown with a 
nice old lady, a retired kindergarten teacher who was slightly 
deaf and didn't care how much music we made as long as we 
didn't do a lot of drinking- -which we didn't do. 

I guess working on her career was more and singing. She 
was still taking singing lessons until after Artie was born, I 
know for a while after that, and was going into New York to 
work with an accompanist. But that's a very tough business to 
try. She had a beautiful mezzo soprano voice--! have some 
recordings of herbut she never got any opportunities really 
to be a singer. It's just a tough business. William Warfield 
was also studying with Yves Tinayre at that time, and he's had 
a successful career. 

Stan Morgan and the Solid State Group 
[Interview 4: September 12, 1996] I* 

Schawlow: When I went to Bell Labs I went into the so-called solid state 
physics group, which was headed by Stan Morgan, who had been a 
physical chemist. He was a very nice person, very easygoing, 
quiet sort of person, but very capable. He didn't tell us what 


to do, which was difficult of course. I didn't know what we 
were supposed to do, particularly since I was working on 
superconductivity and had to find out something to do. The 
group was a remarkable group and I used to wonder at that time 
how many of them would be famous ten or twenty years from then. 
Really, all who stayed active in physics did achieve big 

They included Walter Brattain, who had already been co- 
inventor of the transistor and did get a Nobel Prize soon 
after. I remember the day when he got the prize the telephone 
company very quickly managed to intercept his calls somebody 
would answer them for him. But he did come to our afternoon 
tea, which was held every day. I remember him looking at the 
newspaper and commenting adversely on some of the things it was 

One of the things I remember about Brattain is really worth 
mentioning. He told us his father was a prospector and was 
working up in the mountains stillhe must have been fairly old 
by that time. But he was several miles from the nearest store 
of any kind, and they [the store] had a telephone, and the only 
way to reach him was to send something to him care of this 
place. Well, Walter somehow didn't want to make it too public, 
so he sent a telegram saying: "Transistor men win Nobel Prize." 
When it reached his father it said: "Your sister won the Nobel 
Prize." [laughter] 

That group included Phil Anderson, a theorist who later got 
a Nobel Prize; Conyers Herring and Gregory Wannier, both very 
distinguished theorists. And they were people who were willing 
to talk to you if you had any questions. Conyers has been at 
Stanford for some years since he retired from Bell Labs, still 
active. A very encyclopedic theorist, he knows everything, 
practically, and has made many important advances. 

Also Bernd Matthias, who was kind of an alchemist, I think. 
He kept inventing new compounds for superconductivity or 
ferroelectrics. There were a few others who dropped out. John 
Gait, who had done distinguished work, went into management and 
later was one of the top people at the Sandia Corporation which 
was then being managed by Bell Labs. 

Riess: Were you all more or less the same age? 

Schawlow: No. Well, I don't think there was anybody much over forty. 

Well, Brattain was. They were all fairly young. Some of the 
theorists I think were older- -Wannier and Herring. Anderson 
was young. He's younger than I am. 

Riess: You said Wannier? 

Schawlow: Yes. He later became a professor at the University of Oregon, 
[laughs] He was Swiss, and they begged him to come back to the 
University of Geneva, which he did for a year, but then he came 
back. He said he couldn't stand the food, it was too rich. 

Riess: It sounds like one of the real pluses of working at Bell Labs 
is that notion of a group. 

Schawlow: But they didn't work on the same problems. You could discuss 
anything and-- 

Riess: What defined a group then? 

Schawlow: Well, they were in the same department. Yes. 

There were personal matters involved. For instance, 
Brattain had worked on semiconductors and co- invented the 
transistor but he couldn't stand Shockley, and that's why he 
was with Morgan rather than Shockley. There are many people 
who couldn't stand Shockley I think, though Shockley was 

Morgan was the head for about five years or so. He then 
became head of the chemistry department, which was another step 
up. They changed the title. Ours used to be known as a 
subdepartment, and then there was the department, the physics 
department which was headed by [S.] Millman, who was also 
another easygoing guy but very capable. He had been one of 
Rabi's group at Columbia before, and he was the one who 
recruited me for Bell Labs. Then there was the general 
department which was under Addison White. 

Later they inflated the titles so that the subdepartments 
became departments and the departments became laboratories, I 
think. So the department head became a laboratory director. I 
forget where it went from there. I remember joking at the time 
that they should inflate all the titles so that the staff 
members like myself should be called research executives and 
the technicians would be associate research executives, 
[chuckles] But I don't think they adopted it. Actually, we 
were known only officially as members of the technical staff, 
but I've always put in my biography that I was a research 
physicist, which really was what I was but the title was just 
"member of the technical staff," like all the engineers and so 

We also had Richard Bozorth, who was older but had a very 
distinguished career in magnetic materials. I remember before 


I came there, I read an article in Reviews of Modern Physics 
reviewing magnetic materials and it apparently was also being 
published in Encyclopedia Britannica, the same article, and it 
was beautifully writtenand it was by Bozorth. 

The custom then was that each experimentalist had a 
technician working with him. I had Jerry Caruso for a while, 
but he didn't like what I was doing so he switched to another 
department . I had to find another one and then George Devlin 
came along. Now, he had an unusual background. He was quite 
young. He had never--! guess he had finished high school, but 
he certainly had no college. But he had been a champion model 
airplane builder, and I thought that shows he's pretty good at 
building things. 

He turned out to be very, very smartbut totally 
nonmathematical. I tried to get him to take college courses 
and go ahead, but he just couldn't manage math, not even 
arithmetic. But he could think intuitively about things, 
extremely well, and he noticed things that I didn't notice 
about the experiments, so he was really indispensable. He 
joined me perhaps around 1953 or so and was with me until the 

Riess: Were these people like Caruso and Devlin freefloating at Bell 

Schawlow: No, no, they were assigned to a particular scientist or 

Riess: What had Devlin been doing before? 

Schawlow: Well, he was pretty young; maybe he hadn't been doing anything. 
I don't know. But he really did a good job. 

Riess: Did he understand the experiment? 

Schawlow: Yes, he could understand experiments very well a good 

understanding of physics, but in a nonmathematical way, which 
actually suited me pretty well. 

There were others in the group, like Ernie Corenzwit who 
worked for Matthias, and was very good at fabricating the 
materials that Matthias wanted made. Matthias, Herring, 
Anderson, Brattain, and myself all became members of the 
National Academy of Sciences. Wannier never made it, which was 
really regrettable. He was on the ballot quite often, but when 
he moved to Oregon he was sort of out of sight, and somehow 
never got enough votes. 

Riess: Is one elected by the entire Academy? 

Schawlow: Eventually, yes, but it's a very elaborate procedure, where the 
individual sections, like physics, they even have subgroups 
that try and pick out nominees and the section votes on it. 
The top ones in that go on to the class committee which 
includes geology and astronomy, and mathematics I think. 

I'm sure they must have a lot of fighting in those 
committees because they have to rank order them, and then when 
they get on the ballot, you have to vote for a certain number 
in every class. People in other classes don't really know 
anything about the candidates say in the physics class, people 
in biology or something like that. So they tend to vote for 
the ones that are picked out by that class as being the top 
candidates. When you can get through these several filters, 
you may get elected. 

Riess: Would you say Stan Morgan particularly brought you along as a 
group? Or is it just happenstance that all these splendid 
people were together? 

Schawlow: We were hired by various people. 

Bell Labs had a very extensive recruiting system then. 
They would have a contact at each of the major universities who 
would know the professors and would go there every year and 
ask, "Who are the good people coming out this year?" Millman 
was from Columbia, he went to Columbia, and I guess Townes, 
maybe others told him about me and so he brought me over. I 
was interviewed by Ad White and by a number- -you go around and 
talk to a number of people there, and finally they decide they 
want you. 

It was a very thorough recruiting. They [Bell Labs] had 
people at Berkeley. I was recruiting at Toronto for some years 
when I was at Bell Labs. You recruit not only for your own 
department, but for others that are not too distant. 

Riess: You introduce this by saying that Stan Morgan really didn't 

tell you what to work on and that was a problem, yet somewhere 
along the way in the hiring and the recruiting they must give 
you a pretty clear sense of what they want you to do there. 

Schawlow: They had claimed that the purpose of the research department 
was so that they would be in touch with all the relevant 
technical and scientific fields, so that if anything that they 
should know about came along, then they would know about it. 
They felt the best way to keep informed was to have people 
actually doing research in these different fields; the 


alternative might be having somebody sit in the library, but 
they would be a year out of date at least. If you're in that 
field, and you talk with the other leaders, you can really know 
what's going on. 

I was hired because John Bardeen wanted somebody to work on 
superconductivity, but as I think I may have already said, by 
the time I got there he was gone. But I wanted to try and work 
on superconductivity. I didn't see anything else around that I 
particularly wanted to do, so I did that. 

Working up to the Laser 

Riess: Okay, about this "not seeing anything else around that you 
particularly wanted to do," you and Charlie had a close 
relationship, a family relationship and everything, and the 
maser was under development at Columbia. 

Schawlow: Well, as I told you, I am one of the most anti-competitive 

people you ever met. I wouldn't think of competing, especially 
with Charlie, who was very good. 

I did do a little work on nuclear quadropole resonance when 
I first came there. I heard about it and it looked so 
easyand it turned out to bethat I did some work on that, 
wrote a couple of papers on it. [laughs] I remember I did some 
work on resonances in the ultrahigh frequency region, that is 
couple hundred megahertz. I had found one resonance in a 
bromine compound and I couldn't find the other one. I thought 
I knew where it should be because we knew something about where 
the bromine resonances were in sodium bromate. 

By scaling from chlorine, which is a somewhat similar atom, 
I thought I had the higher frequency isotope, and I kept 
looking for the lower frequency resonance--! think the one I 
found was somewhere like 180 megahertzand I couldn't find it. 
Then I thought, "Well maybe it's the other way around," it's up 
around 215 or so. But there was a television station there. I 
found that the television station was only off the air from 
midnight to six a.m., or something like that. So one of the 
very few times that I came in at night, I came in and looked 
and found the resonance I was looking for. 

The apparatus I used was extremely simple and primitive- 
looking. I remember I had a visit from Professor Gutowsky from 
the University of Illinois. He took a look at this and said, 
"Well, I've never had much luck with simple apparatuses," 


something like that. Or "primitive," I forget what he called 
it. Well, it was pretty crude, but I was just sort of 

I had some reason to do it because these were moderately 
sharp resonances and they might perhaps have been used for 
frequency standards. But I measured the temperature dependence 
of themthey "re quite sensitive to temperature, and they 
weren't really awfully sharp, so they were not suitable. I 
mean, 1 did explore them enough to find that and also get a 
little data of interest to the physical chemists although I 
really didn't understand it very much. It gives some 
information about chemical bonding, but not much. 

Riess: You said that to have thought much more about the maser would 
have been competitive? 

Schawlow: Well, at that time it was only the ammonia maser, the other 

kinds hadn't been invented yet. By the time they were, there 
were a lot of people in the field, including a group at Bell 
Labs. In fact, they came around and asked me if I'd like to 
work on masers, maybe about 1956 or "57, and I said no. I just 
really couldn't see getting into that. 

Riess: But at the same time weren't you and Charlie talking about the 
potential for an optical maser? 

Schawlow: No, we didn't talk about that at all until the fall of '57--I 
think it was October. By that time he was consulting at Bell 
Labs and we had lunch together and decided to cooperate. I had 
begun thinking about trying to find ways to make infrared 
masers; I hadn't gotten very far but I was thinking about it. 
Then Charlie came and said he'd been thinking about it too. 

See, the original idea of the maser was to get wavelengths 
shorter than you could produce by radio tubes, but it had not 
succeeded in that. It had other uses: an atomic clock and 
sensitive amplifier for radio astronomy and radar and so on. 
The interesting question was: could you extend it farther? 

Well, my thoughts were to just take the next small step, go 
into the far infrared, closer to the microwaves. But Charlie 
pointed out that in fact it might not be any harder to go to 
the visible or near visible region. That appealed to me 
because there was really at that time very little information 
about spectra in the far infrared, and the spectra are the raw 
materials that you have to use. So we agreed to think about 

We had to, first of all, see whether you could get enough 
excited atoms at one time. A maser or laser requires that 


you have more atoms in the excited state than in some lower 
atomic state or molecular state, and this doesn't ordinarily 
happen. In fact, in thermal equilibrium at any temperature 
whatever, no matter how high, there are always more in the 
lower states than the upper states. 

But he [Townes] had shown in the ammonia case that he could 
do it, he could find a way. Well, in the case of a microwave 
maser, the relaxation is very slow: that means the molecules 
when they are excited don't radiate very fast; they'll stay 
excited so you can accumulate enough for the purpose. Whereas 
in the optical region they usually emit their radiation in a 
millionth of a second or less. But it turns out that that 
doesn't matter too much. Still, we had to get some specific 
examples and try and calculate how many that we might need. 

I started to look into the alkali metals: sodium, 
potassium, rubidium- -because they have the simplest spectra. 
In a way, that may have been a mistakewell, those were the 
things we could get information about, but some of the more 
complicated ones are more useful. 

Riess: Was this an issue of getting materials from Bell Labs? 

Schawlow: No, no, this was purely theoretical. What we did was to go to 
the library and search. Although the spectra were pretty well 
known, widely published, what was not so widely available was 
the transition probabilities, or lifetimes of excited states. 
They're closely related because if the atom is going to be 
stimulated, it needs to have a certain coupling to the 
electromagnetic field. And that same coupling is what causes 
the radiative decay. You can't think of the spontaneous 
emission as really being stimulated emission, stimulated by the 
vacuum fluctuations. In the microwave region, it would be the 
thermal radiation around; in the optical region, it's the 
fluctuations in the electromagnetic fields of the vacuum. It 
has no average field, but it does fluctuate. 

It turned out, as a matter of factCharlie had the 
equation and I turned it this way and that to try to see what 
it implied, the maser equation it turned out that it didn't 
really matter what the lifetime was because if the lifetime was 
short, you didn't need very many because they were more 
strongly coupled to electromagnetic fields. If the lifetime 
was long, you had to have more. So the number didn't matter. 

What did matter was the efficiency, what fractions of these 
atoms would be stimulated to emit in the particular decay 
channel that you wanted, at the particular wavelength or 
transition that you wanted. If they were all going to go off 


at some other wavelength, then that made it inefficient. So 
that was something that we realized, that it was more important 
to have good quantum efficiency. 

The second thing: we had to know the absorption strength to 
know how much light we would need to excite the atoms. We 
didn't think of anything at that time except exciting them by 
light from another kind of a lamp. A method of optical pumping 
was known in connection with Kastler's work using light to 
excite atoms to an excited state from which they decay to a 
particular chosen level of a ground electronic state. But we 
were in thinking of optical pumping in a different sense, as 
using light to get atoms into the upper state so we could get 
the maser action. One of the advantages of the alkalis was 
that you could get lamps of the same material and they would 
have the right wavelength for pumping. 

Now, of the alkalis, I concentrated on potassium, which was 
wrong for some reasons. The reason I did it was a very foolish 
one. I mentioned how hard it was to get equipment when I first 
came, but the one thing I did get was a wavelength 
spectrometer, which is a visible spectroscope: you look through 
the thing in the visible range. I got that for measuring the 
thickness of thin films. I had that around, but it only worked 
in the visible region. Potassium had the interesting property 
that the first and second absorption lines in the spectrum were 
both in the visible, one in the deep red and one in the blue-- 
whereas all the others, at least one of the lines was out of 
the visible spectrum, either in infrared or the ultraviolet. 

The reason it turned out to be bad was that potassium is 
very reactive chemically. After we'd finished our paper, 
Charlie put two students and a visiting scientist on trying to 
make a potassium laser, and they didn't have much luck because 
the slightest trace of oxygen in the device would quench the 
fluorescence. But we could work it out and that's what we used 
in the publication. You could see that with reasonable lamps, 
you could get enough excited atoms to get stimulated 
emissionget enough gain so that with reasonable mirrors you 
could get reflection. 

It's funny, at first we thought of the thing really as like 
a maser with a box resonator. It's curious that we had "L" was 
the width of the box, and "D" was the length--! think that's 
the way it was in the paper toowhereas obviously "L" is the 
right thing to use for the length and "D" for the diameter. 
But that was something we inherited from the maser. I forget 
whether we turned that around before we finished the paper or 
not. I don't think so. 


As I say, I spent a lot of time looking in the Landolt- 
Bornstein Tables for transition probabilities. These are 
monumental tables published in Germany, many volumes. There 
wasn't much information about transition strengths, but there 
was enough for these simple atoms. 

L J.W1. L.11COC OJ.Ui^XC at-UUiO. 

for going through that. I know you've written papers 
er this in a very clear way. 

Riess: Thank you ior going i_nrougn mat. i 
that go over this in a very clear way 

Mode Selection 

Riess: What I think is interesting at this point is to get an 

understanding of why Bell Labs called Charlie back to consult, 
what their motivation was. Did they think he would come back 
and work on this with you? Was that the intention? And during 
that time, where did you meet? Did you meet there, or was this 
all happening on the phone? What were the circumstances. 

Schawlow: They called him back because Nicholas Bloembergen had invented 
the solid state maser, which was obviously a very sensitive 
amplifier for microwaves, and was tunable. The first one was 
built at Bell Labs. Bell Labs very quickly got a license, I 
guess even before the patent was issued, and [H.E.D.] Scovil, 
[G.] Feher, and [H.] Seidel built the first tunable, solid 
state maser. 

I think they wanted Charlie to help with the progress of 
the maser program. They did not think at all about optical 
masers or lasers. This was something just off the books. He 
came to Bell Labs from time to time to see the maser people, 
and we would talk in my lab . 


Riess: How did the two of you work together? 

Schawlow: He gave me, I think, some notes that he had made. He had 

originally proposed thallium and I decided that wasn't going to 
work because the upper state would empty faster than the lower 
state so that you wouldn't be able to get an inversion. Well, 
I'm not sure I was clever enough to find an alternative way to 
use it, but he accepted my arguments at the time, so that's 
when I switched to looking at the alkalis, potassium in 

We would talk for maybe half an hour or so and I'd tell him 
what I'd been doing. One illustration of that is that we did 


discuss the question of mode selection. He had thought that 
you'd use some sort of a box with reflecting walls that would 
be much bigger than the wavelength. For the maser, you could 
have a box that was comparable in size with the wavelengths so 
that the wave would only fit in one way, and that would mean 
that you would get one pure wave stimulated. On the other 
hand, in the optical region, the wavelength is 30,000 times 
shorter and if you could make a box that small, you wouldn't 
have any room to put any atoms in it. (Actually, it's been 
done since then.) 

So we thought, from the beginning, of something of 
convenient dimensionscentimeters or more. Martin Peter, a 
Swiss scientist who had gotten a Ph.D. at MIT with Strandberg, 
had worked some on mode selection there, and he kept urging me 
that we had to find a way to select one particular mode of 
oscillation. Well, Charlie felt that even though we couldn't 
do that, that somehow a few modes would probably have higher 
gain or lower losses than the others, and might stand out; it 
might be jumping from one mode to another, but it would be 
enough different from an ordinary lamp that you could see it. 

Well, under Peter's urging I was thinking about it. 
[laughs] My sister claims it was while I was shaving, but I 
thought of using two small mirrors far apart. This is like the 
Fabry-Perot interferometer that I'd used as a graduate student, 
but not really like it, because those plates were big and close 
together and these would be just two tiny little plates at the 
end of a pencil-like column of active media. I thought, "Oh 
boy, the wave has to go"--simplemindedly--"if the wave's going 
to get from one mirror to the other it has to go straight along 
the axis, otherwise it'll go off and be lost." That's why I 
estimated that you could get the radiation down to an angle of 
a few degrees. The wavelength would be selected by the atoms; 
they would only support a small range of wavelength. 

I told that to Charlie--! think the next day I happened to 

see himand he said, "It's better than that, because the wave 

is going to bounce back and forth many times, and therefore 
we'll get really good selection." 

Riess: So that was an exciting moment. 

Schawlow: It was, yes. I think at that point we felt that we had it, and 
the only thing left was to write it up. We could have tried to 
build one, but I didn't have any equipment, and I had only the 
one technician, and I didn't think of asking for help which 
maybe I could have had, I don't know. But it just seemed 
impossible to build one for me. 

Riess: And Charlie couldn't have gotten Columbia organized? 

Schawlow: He did, actually. Somewhere around February or March of '58 we 
made the decision that we should write it up. But instead of 
trying to build one--well, I think we both agreed it was 
important to write it up first because of what had happened 
with the maser. I think I've told you about that already, that 
he had the maser idea, and in those days it was not considered 
proper to write a proposal of what you were going to do but 
rather to do it. That almost cost him a Nobel Prize, except by 
accident it was published. So we decided to publish it rather 
than try and build it. 

Riess: The sense of excitement--! want to know what it was like. 

Schawlow: It was exciting to have the ideas that fitted together-- 

couldn't be sure, though, that we hadn't overlooked something. 
When we presented a draft of the paper for review, some of the 
theorists including Clogston gave us a hard time because they'd 
never heard of such a resonator. It was a very strange one 
with open sides. They said, "How do you know what the modes 
will be in that kind of a resonator?" Well, I didn't know. 
All I had was this simple-minded view that if the wave was 
going to go from here to there, it has to go straight back and 

Charlie did put in a little stuff about how much 
diffraction would spread it. In fact, diffraction is 
really what makes it workthat is, the spreading of a wave 
around an obstacle. You see, you start out with one atom, say, 
and it emits some radiation, and it'll be a circular wave, 
though, spreading out, and some of it travels along the 
direction of the axis and gets reflected and stimulates other 
atoms to go the same way. The light will spread out as it goes 
back and forth until it fills the space within the mirrors. 
This is by the process of diffraction. 

[laughs] I gave a talk at a conference in 1961 in England, 
an optics conference. Professor Hopkins there said, "I don't 
understand how the wave fills the resonator." I tried to 
explain but he said he still didn't understand! We didn't have 
a rigorous theory for this kind of resonator. Not long after 
that was developed by Gardner Fox, and Tingye Li. They did a 
numerical calculation of the waves between two such resonant 
mirrors in the resonator and came out with a pretty good 
description of it. 

It's interesting, several people said, "Why don't you use 
spherical mirrors"--there is a spherical Fabry-Perot--"because 
the losses would be less." Indeed, George Series suggested 


that in 1959. But in fact, you depend on the losses. The 
ratio of the losses for the different modes is the same, but 
the absolute value of the losses is larger for the flat 
mirrors. And if you're working with a solid material, you have 
pretty large gain and you need fairly large mirror loss to 
exceed the loss from scattering in the material. So the losses 
at the mirrors have to be big enough so that only the highest 
gain mode survives, whereas in a gas laser they do use 
spherical, or sometime one flat and one spherical mirror, which 
have lower losses, because they have very much lower gain. 

Riess: You mean spherical or do you mean concave? 

Schawlow: Concave, yes, parts of a spherical surface. One kind uses a 
flat mirror and then the other end is a spherical, concave 
mirror whose center of curvature is at the other mirror. Well, 
people worked out the losses; in certain spacing between the 
mirrors the losses are large. 

By about 1963, that's after I left Bell Labs, I was 
beginning to get annoyed by these people saying you needed to 
have very low loss mirrors and to use concave mirrors for 
everything. So I actually suggested that you might make 
mirrors that are curved the other way, that are divergent, for 
high gain materialsand indeed, people do that for high power 
now. I didn't bother to patent it or anything, but I did 
mention it and it's been developed; the theory and all that's 
been worked out particularly by A. [Anthony] Siegman. 

Riess: You were just saying it to make the point. 

Schawlow: Yes. 

Riess: Your sister said you got the idea shaving. Did you? 

Schawlow: I suppose I must have told her that, but I don't remember. I 
really don't remember it, any more than I remembered rooming 
with Charlie in Washington! 

About the Patent The Smell of Success 

Riess: We've talked before about your not having filled many 

notebooks, but you did write down your ideas in February 1958. 

Schawlow: Unfortunately that was just before I had thought of the two 
flat mirrors. I was thinking about it. I thought of things 
where you might use diffraction gradings on the walls that 




would reflect different wavelengths differently, at different 
angles, which later have been used by other people to tune 
lasers. But I didn't do anything more with it. I think I did 
describe the potassium system. 

I'm not sure exactly what was in those notes because I have 
only one page of it which the Bell Labs people copied and sent 
to me. But I don't have the rest of it. 

You put these ideas downyou knew you had a big one here? 

Well, yes, I thought it might be something good, that we were 
kind of getting there. I think by that time I decided that the 
potassium system could be made to work, so that I had something 
to write about, and I did put down our thoughts on mode 





Then I had it witnessed by Sol Miller, who was one of 
Charlie Townes" former students, who had a lab next door, I 
think it was. They had a system at Bell Labs where they would 
keep people separate departmentally, but they would mix them 
geographically, deliberately, so you'd get to know people in 
other areas of the company without having any responsibility to 
work for them. So I told him about it, he read it, and 
witnessed it. That was Friday. And then I was rather 
horrified on Monday to learn that he had gone to IBM. 

How extraordinary! And he didn't tell you. 

He didn't tell me, no. I think it was that close, yes. 
don't think it did any harm. 

But I 

You also say it seemed best to publish without waiting for 
experimental verification. But you had to circulate the 
manuscript for technical comments, and also to the patent 

Yes. And the patent department didn't want to do anything 
about it. But Charlie sort of insisted. They said, "Well, 
this is a maser, just a different wavelength," you know. They 
didn't realize the importance. And I think really the patent 
wasn't nearly as good as it could have been if they or we had 
thought it was important. 

I had never patented anything before, but Charlie had and 
persuaded them to file for a patent. We helped them somewhat, 
but we didn't put down all the ideas we considered obvious. 

Something Charlie points out in his oral history is that when 
he had been working at Columbia he was used to talking about 











everything he was doing with everyone around him, but that when 
he was working with you at Bell Labs he didn't talk openly 
about what he was doing. 

Well, I did. I pretty much talked with anybody that wanted to, 
certainly anybody at Bell Labs. Ali Javan was recruited by 
Bell Labs about that time. He had been a student with Charlie 
and then a post-doc. He came out for an interview and I told 
him about it, and he did come to Bell Labs, but he might not 
have. I didn't really try to be confidential at all. I don't 
remember whether I told anybody outside of Bell Labs. I wasn't 

trying to be particularly confidential, 
it was going to work or not. 

I didn't know whether 

Something else you said in a paper was, "Being at Bell Labs, I 
had been pretty thoroughly indoctrinated to believe that 
anything that you can do in a gas could be done in a solid, and 
can be done better in a solid. Al Clogston, my boss at Bell"-- 
he was boss within that Stan Morgan structure? 

No, he replaced Morgan when Morgan became head of the chemistry 
department. Actually he wasn't the immediate one. Ken McKay 
came first. I don't know when Morgan left. It must have been 
after only a few years there, and then Ken McKay. He came in 
and then Clogston. Clogston was very supportive. 

You say he, "encouraged me to, if I wished, drop 
superconductivity entirely and begin studies of possible 
optical maser materials." 


Then you say parenthetically, "Though no one suggested putting 
together a group to build an optical maser." 

That's right. 

"Anything like that I would have to do myself." 

Yes. That's right. Well, I just didn't know how hard it was 
going to be. I didn't realize how easy it would be. [laughs] 
I was very close and I just didn't realize it. 

This is really a Joe Six-Pack question for you: did you smell 
success with this? "We can get this thing patented and we can 
really make out like crazy?" 

Schawlow: No. No, I thought it could be important if it worked. I 

wasn't absolutely sure that we hadn't overlooked something. 
We'd been as careful as we could, but 1 don't know, I'm timid I 


guess. Of course, I didn't know what it was going to be like. 
I thought it might just give microwatts of power at some near- 
infrared wavelength or something like that. And that wouldn't 
be terribly useful. 

Looking at Materials Ruby 

Schawlow: I think I did mention in my articles that I started to look at 
materials. In fact, in the paper, I mention that some solid 
state materials have an advantage because they have broad bands 
to absorb the radiation and still emit it in narrow lines. I 
thought you had to have narrow lines because our equation said 
that the gain was inversely proportional to the line width, so 
the wider the line, the less gain you'd get for a given number 
of excited atoms. I really had a fixed idea that you had to 
have narrow lines, which turned out to be wrong later in some 
cases. But to get started, that's what we needed. 

1 knew nothing about solid state spectra and I always like 
a chance to learn something new, but the only one I knew about 
at all was ruby, which is chromium in aluminum oxide. We knew 
about it a little bit because ruby was by that time being used 
for microwave masers and it was one of the best materials for 
them. So you could find people that had drawers full of ruby 
crystals. One thinks of ruby as a very expensive gem, but 
artificial rubies are not expensive at all. They are made in 
large quantities. They were used for watch bearings in large 
numbers and I don't know what all else. 

Riess: But they have the same properties? 

Schawlow: Yes, in fact they are better than the natural ones for optical 
things, because natural ones are never very large or pure or 
unstrr ned. In fact, ruby always does have some strains in it, 
it's h^rd to grow it without strains. But ruby does have a 
broad absorption band in the middle of the visible so that a 
broad band lamp could pump it, like a flashlamp, a photographic 
flashlamp. It does have a sharp line in the red, or a pair of 
sharp lines called the R-lines. 

So I thought, well, I'll look into ruby and see what I can 
learn about it, try and find out how the line width depends on 
temperaturefor instance, would it get sharp at low 

Riess: This was while you were still there at Bell Labs? 


Schawlow: Yes, yes, we did a lot of work the last two years there. We 
also looked at chromium in a couple of other materials: 
magnesium oxide, which is a simple crystal, like rock salt 
structure, but it couldn't be grown easilywell, it was grown 
for other purposes in some electric furnace, I forget where, 
not at Bell Labs. And also we looked at gallium oxide. 
Gallium is related to aluminum in the periodic table. There's 
aluminum, gallium, indium. 

They had a marvelous crystal grower at Bell Labs, Joe 
Remeika. (Oh, I was going to tell you a story about him.) He 
grew some crystals of gallium oxide with various concentrations 
of chromium in them. We knew that there were other lines in 
the spectrum, and nobody had any idea what they were 
fluorescent lines to the red of these strong R-lines. I 
guessed that they might be from coupling of vibrations in the 
crystal to the emitting atoms. 

However, Remeika grew crystals of gallium oxide with 
different chromium concentrations. George Devlin noticed that 
the strength of these other lines relative to the R-line was 
different in different crystals. In fact, the more the 
concentration, the stronger these lines were. He pointed it 
out to me and I immediately realized that the lines had to be 
due to pairs of chromium ions that happened to lie close 
together, because the higher the concentration, the greater the 
chance of having pairs of ions. So we spent a good bit of 
time, both there and again at Stanford, studying these pair 
lines and trying to find out which pairsthe crystal is only 
moderately complicated, but I think there are a number of 
nearest neighbor pairs. There's a pair there right along the 
symmetry axis, and various pairs at different angles that had 
different distances. 

In fact later at Stanford we put stresses on the crystal in 
different directions to see which lines shifted most with a 
particular direction. But before I leave Remeika, I must tell 
you an amusing story. This was earlier. There was a time when 
people thought that ferroelectric crystals would be useful for 
computer memories. Now ferroelectric doesn't mean it has any 
iron in it, but it has an electric susceptibility that 
resembles the magnetic susceptibility of a ferromagnetic 
material. However, people had trouble with these things not 
being good insulators, they would act as semiconductors rather 
than insulators and were too lossy because the currents would 
flow through them. Remeika found that he could grow good 
crystals if he did them in an iron pan, so they got a little 
bit of iron in them which acted as acceptors to cancel out the 
donors in the material. They called this Project Ironpan. 
[laughs] They kept it secret for a while. 



Walter Mertz, who was another physicist in the group who 
later went back to Switzerland and became head of the RCA lab 
there, was working on these crystals. He gave a talk at a 
meeting of the American Physical Society. [R.M.] Bozorth was 
the chairman at this, but he didn't know about this particular 
project, so after Hertz's talk he asked him innocently, "Can 
you tell us what was the difference in these crystals that were 
so much better than the ones people had?" And of course he 
couldn't tell them, which was embarrassing. [chuckles] 

When you left Bell Labs, were you able to bring George Devlin 
to Stanford? 

Schawlow: No, I offered him to come, but he didn't want to come. He went 
instead to stay to work with another of Charlie Townes' former 
students, Stan Geschwind. And he stayed with him for twenty or 
twenty- five years. Then he retired early and took a job at the 
NEC Laboratory in Princeton, so he had a good pension, and also 
probably a good salary. 

Riess: What is NEC? 

Schawlow: NEC is Nippon Electric Corporation, universally known as NEC. 
That laboratory is headed up by still another one of Charlie 
Townes' students, Joe Giordmaine, who had been at Bell Labs 

Riess: Were you at Bell Labs long enough to get a pension? 

Schawlow: No, not one cent. In those days it didn't vest at all. I was 
there for ten years, but I would have had to stay until 
retirement to get anything. I think they've changed that. It 
did leave me a little annoyed but I knew that was the rule. 

Where were we? 
Riess: You were working on the ruby. 

Schawlow: We found out that these other lines were caused by the 

interaction of chromium ion pairs. And I realized that these 
pairs would have several levels, not Just the one ground state, 
but they would have several levels near the ground within a few 
hundred reciprocal centimeters. 


Schawlow: We found the same thing in ruby. The lines had been known in 
ruby for fifty years, but nobody had any idea what they were 
about and we were the first to discover that they were caused 
by chromium ion pairs. 


We also realized that the lower levels of these particular 
pairs of atoms would be split by maybe several hundred wave 
numbers. (A wave number is equivalent to roughly a degree 
absolute.) So if we could cool it down to low temperatures we 
could empty the upper ones among this group of lower ground 
levels. Instead of having just one ground level, we'd have an 
array of a few of them, and then we could cool it and get the 
empty lower state. 

I thought, "Boy, that's what we need." We may not be able 
to put very many atoms in the excited state and if we have an 
empty lower state, then we'll get gain immediately. I actually 
tried that, very sloppily, with what I had around. I still had 
an old Dewar from the superconductivity days. 

Riess: An old what? 

Schawlow: Dewar, D-E-W-A-R. That is a vacuum flask for getting low 

temperatures by insulating liquid helium. I had a of dark ruby 
polished; the ends were polished flat and parallel as near as I 
could get. (I still have the order for that.) I cooled that 
down in this thing. But then I didn't buy a big flashlamp, 
which I should have but I didn't. I just had a stroboscope 
sort of thing, I think a General Radio Strobotac, which is only 
about twenty-five watt secondsnot a very powerful flash at 
all. I tried that and nothing happened so I just put it aside. 

Riess: This story is painful in many respects which are obvious to 
you, too, that the materials that you keep--. 

Schawlow: I was stupid. 

Riess: No, no. No! It's almost like you were programmed from those 
early days of Toronto not to expect to be able to get hold of 
what you needed if you wanted it. 

Schawlow: I think that's right, yes. I think that's right. I just sort 
of learned to make do with what I have. I did not have an 
aggressive training. I think other students who came in had 
been in labs where they had money, particularly in the years 
like the late fifties and sixties when the government was 
putting a lot of money into research and people got anything 
they wanted. Yes, I think that's true. 

Riess: But then on the other hand maybe it's given rise to more 
ingenious solutions. 

Schawlow: Yes. 


Well, but then I really put my foot in it. I gave a talk 
at the first Quantum Electronics Conference which was held in 
1959 after we'd published our first paper. I mentioned about 
the ruby pairs and said that they would be good for an optical 
maser, but that the R-line was not suitable for maser action 
because it went to the ground state. 

Well, [Ted] Maiman next year proved me wrong on that, and 
one of the reasons I said that was partly because I didn't 
think quantitatively, but there were no less than three 
measurements of the quantum efficiency of atoms when they're 
excited to the upper level of the R-line, and they all were 
between one and three percent. I don't know how they were so 
far wrong, but if it had been that low then it wouldn't have 
worked. In fact, we did some experiments which really 
indicated that it was much higher than that but we didn't make 
a direct measurement. 

The experiments we did were on radiation trapping in ruby. 
That was really almost the most fun experiment I ever did. I 
had known from work in Toronto--! 'd heard Crawford talk about 
itthat if you have a lot of atoms, then when one emits 
another one may absorb it, so the light has a hard time getting 
out, and the apparent lifetime will be longer. I forget the 
exact course of the thinking: I think that sapphire, which has 
only a very tiny trace of chromium in it, did give a lifetime 
of something like three milliseconds. The papers exist, we can 
check those things. Whereas the ruby was considerably longer 
than that, I think as much as twelve milliseconds or something 
like that. So I thought maybe it might be trapping. With the 
collaboration of Darwin Wood of the chemistry department- -he 
had a diamond saw and cut us a thin slice of ruby, and we 
measured the lifetime. It was somewhat shorter, but not as 
short as the really dilute material. 

So then he ground it up for usthis was all done in a day 
or so and it got shorter still, but still not as short. 
Finally we took some of this black stuff that's like 
plasticine, it's called Apiezon Q, which is used for vacuum 
work, and we embedded the grains in the surface of this black 
stuff so that one grain could not see the other. And we 
finally got the lifetime as short as you got for really dilute 

Now that should have shown us that the quantum efficiency 
was pretty high, because these things were able to catch it and 
re-emit it. 

Riess: Why are you saying that was fun? What made it fun? 


Schawlow: Oh, well we did it so quickly. You try one thing, you get some 
results; you have an idea and try that, try the next one. It 
was really fun, I really liked that. That's what I consider 
fun, when you start getting some results and that suggests 
something else, and you can try that out. Usually though you 
have to do a lot of preparation to try another thing. In this 
case we were able to do it right away. So, we did this work on 
radiation trapping and that really did show the lifetime was 

Ted Maiman's Work, and Publication 

Schawlow: Maiman, I think, made his own measurements on the fluorescence 
efficiency, did a quantitative job, and realized that he could 
actually excite enough atoms to invert the population. And he 
did so. 

Riess: And he built the first one. 

Schawlow: He built the first one that worked, though there are some funny 
stories about that too. 

Riess: Go ahead. 

Schawlow: Well, there was a very sad story about this publication. He 
had a paper in Physical Review Letters, published I think in 
May of 1960, in which he did some excitation of ruby. What was 
it he measured? I thought he was working on optical pumping of 
the ground state of ruby and didn't pay much attention to it, 
although it was sent to me for refereeing and I said it was 
okay- -except I made him put in something what concentration of 
ruby he was using, how much chromium. 

But then in June or early July, he got his laser working, 
and he sent another letter to Physical Review Letters and it 
was rejected. Now Physical Review Letters had published an 
editorial saying there 'd been too many maser papers and they 
weren't going to print any more maser papers. And he, I guess, 
called it an optical maser and they rejected it. He thought 
they'd done it because they wouldn't take any more maser 

In fact, a few years later I talked with Simon Pasternak, 
who was one of the coeditors of Physical Review Letters, and he 
told me that they hadn't bothered to referee it. They felt it 
was a case of serial publication, whereas they wanted people to 
finish a project and write up a full report rather than 

Riess : 


dribbling it out in little bits and pieces. Since he'd just 
had a paper published on exciting ruby, they didn't bother to 
have anybody referee it. 

Well, Maiman didn't know. He thought it was because it was 
masers and he didn't ask for another referee, which is the 
normal thing. Instead, he submitted it to the Journal of 
Applied Physics and they said they would publish it. But 
Hughes was quite excited about it and they had a high-powered 
publicity agent they hired for the thing, and this guy sent 
around preprints of Maiman 's article for Journal of Applied 
Physics to various trade journals. One of them, British 
Communications and Electronics, published it, without 
permission. They did it quite quickly, I think in August. 

They'd had a press conference in July, that was when they 
announced it. I had a preprint of it- -so did a number of other 
people. This press conference got a lot of attention. 
However, once this British Communications and Electronics had 
published it, the Journal of Applied Physics said they couldn't 
publish it because it had already been published. So then he 
finally sent a slightly abridged version to Nature, and they 
published it I think around September. 

In the original article he said only that he used a crystal 
of centimeter dimensions. And I think he made some remark that 
because of the reflections from the side walls it wouldn't 
produce a beam- -I don't know exactly. So we thought, well, 
we'll get smart. At that point several people at Bell Labs 
quickly got into the thing and set up big flashlamps. 

Under you? 

Schawlow: No. 

Riess: But you were still associated with it? 

Schawlow: Yes. They were friendly. There were two groups. One was with 
Bob Collins, Robert J. Collins, and Don Nelson. They were in 
the same building and we talked quite a lot. In fact I had 
talked with Collins earlier about potassium lamps, how much 
light you could expect, and that sort of thing. So they built 
up a ruby laser. 

Maybe I ought to go back a minute and put in something I 
forgot about. In this first Quantum Electronics Conference 
paper I wrote up that the structure of a solid state optical 
maser would be especially simple: just a rod with the ends 
polished flat and parallel and coated to reflect light, and the 
sides left open to admit pumping radiation. Well, when I saw 


the picture of Maiman in the newspaper with a little rod of 
ruby, it was exactly what I had in mind. 

Anyway, the people at Bell Labs thought they would check 
the predicted properties. I couldn't resist joining in some of 
that with Collins and Nelson. I had a good spectrograph so we 
could measure the line width and found that it was sharper- -the 
stimulated fluorescence was narrower, as predicted. 

Riess: Say that again. 

Schawlow: The emission bandwidth of light emitted by the laser was in a 
narrower band than the spontaneous emission of the ruby by 
itself. That is, at lower powers it would have would have 
emitted over a certain broad wavelength, but the only part that 
was stimulated would be at the center of the emission line 
where the gain was highest. So we verified that. 

I had a good oscilloscope. It's amusing. I think I told 
you that after I'd been there about five or six years they 
loosened the purse strings for apparatus. People could buy 
almost anything they wanted. I didn't buy anything very 
extravagant, but when we got into this laser materials I 
decided to buy the best oscilloscope I could find on the 
market, the most expensive one. This was a dual beam 
oscilloscope from Tektronix, so it could display two traces at 
the same time. 

Well, one of the things we did was look at the time 
development of the laser pulse. George Devlin asked, "Is there 
any sign of hysteresis?" That is, a thing having friction 
being slow to start up and slow to stop. We thought, let's 
look at the details of this line. The dual beam oscilloscope 
turned out to be exactly the right thing because we could 
spread out one of the traces, so that the whole scan was only 
about half a millisecond or so, which was the length of a laser 
pulse. You could see there were spikes, that is, it was not 
going all at once but in narrow spikes. So we were the ones to 
discover that. It's particularly so for the ruby, not for all 
other lasers. 

Riess: So does this mean then that you put pen to paper? 

Schawlow: Well, in a short time. But then this other group, Garrett and 
KaiserGeoffrey Garrett and Wolfgang Raiserwas working in 
the other building. They were somewhat more competitive. We 
didn't know exactly what they were doing. 

It was really bothering me. One night I couldn't sleep. 1 
was wondering, now does this thing really produce a narrow 


beam? We couldn't see it in our early ones because we had this 
bright flashlamp which put a tremendous amount of light, lit up 
the whole room- -we really hadn't boxed it in. The next morning 
I came in and insisted that we've got to look to see if we have 
a beam. What we did was just use a camera to photograph the 
spot that it was producing, and indeed it was a narrow beam. 1 
And I thought we should get a narrow beam because we had a rod 
that--I think I had suggested we have it rough-ground on the 
side so that you wouldn't get a lot of reflection from the 

However, a few days later the group of Garrett and Kaiser, 
who were working also with Walter Bondhe was basically a 

Riess: [from several pages later in the interview] Just a footnote to 
something you said before. I couldn't visualize how you could 
only test the focus beam by actually taking a photograph of it. 

Schawlow: Well, it was silly, we didn't really have to, but we had a 

camera which I'd bought for work on superconductivity, looking 
at the powder patterns, a Speed Graphic camera, and you could 
put Polaroid film in it. The reason we needed the camera was 
because the whole room lit up. As I say, we just hadn't boxed 
in the flashlamp. You'd put this thing up close, and you'd put 
a shield around so to shield the camera without shielding all 
the rest of the room, and put it up close to the rod or maybe a 
few inches away, and then see whether you got a spot or not. 

One of the things we did find there is that emission was 
occurring from many separate filaments in the rod. You know, 
one of the reasons why I didn't know whether it was going to 
work was that this ruby was really a very poor optical 
material. It's a very wavy structure in the thing, almost like 
Coke-bottle glass somebody said, so was it possible that the 
wave could go from one mirror to the other without being 
terribly distorted? Well, apparently what happened was that 
there were a number of little small paths that the light could 
go through from one mirror to the end of the other and get 
reflected back. So the thing actually lased in a large number 
of small filaments. 

And you could see that by photographing the end of the rod. 
The obvious way, and we didn't always do the obvious things, 
would have been to just build a box around the whole thing. 
Even a cardboard box would have done to cut out the stray 
light, but we were in such a hurry to try everything that we 
didn't stop to do that. 



crystallographer, but he was polishing the crystals for them, 
and in fact he found good ways of polishing ruby crystals, a 
very wonderful person, he contributed a lot to the techniques 
at Bell Labs. Anyway, it was Bond, Garrett, and Kaiser, though 
Garrett and Raiser were doing the experiments. They had a rod 
that was not ground on the sides, it was just polished, but 
they boxed it in and they could see the spot on the ceiling. 
It was a small spot. It turned out that polishing the sides 
didn't matter. 

By about that time Maiman had also discovered that his 
thing was producing a beam. He didn't publish it right away, 
but Mary Warga, who was the executive secretary of the Optical 
Society of America, very much on the ball with the early laser 
stuff, she got him to give an invited paper at the fall meeting 
of the Optical Society. The deadline for abstracts was the end 
of July and in that he said he had a beam, so he must have had 
it by about then. But it wasn't in print until October [I960]. 

So we had these various properties and we finally agreed 
that we would set a deadline and we would pool everything we 
had and write a letter to Physical Review Letters as of a 
certain date- -I think it was in September. We did an 
experiment with Collins and Nelson to show that the beam was 
coherent; we got diffraction from a single slit. We were going 
to do a double slit, but we ran out of time. So we published 
that. We were careful not to use the word maser in the 
article, but it was published without any problem in the fall 
of 1960. 

You published with Bond, Garrett, and Kaiser? 

And Collins and Nelson. They had a press conference about that 
time, Bell Labs did. There was a good bit of jealousy there. 
They didn't want me to come first in the program, they had me 
come somewhere in the middle to explain how the thing worked. 
But they didn't fool anybody, the newspapers knew who had 
started all this, but the jealousy was there all right. 

I had promised to give a talk at the Northeast Electronics 
Conference, and I had to send around an abstract for clearance. 
Garrett and Kaiser objected and said something about shouldn't 
all the authors of this paper be included or something like 
that. I was really very upset, and I complained to Clogston. 
He said, "Leave this to me, I'll handle it." But I said, "If 
necessary, I'll just talk about the things before our 
experiments." Anyway, I felt that they were jealous. Also, 
there was increased secrecy, people doing things and not 
telling you. 


One thing of course I noticed was that all of a sudden I 
had more people talking to me than I had time to talk with, 
whereas before on superconductivity I was really all alone and 
nobody cared about what I was doing. 

Riess: This business about hysteresisdid George Devlin get credit? 

Schawlow: I'd have to look that up. I did put him on a number of papers. 
I don't think so, no, because that was included in a paper 
where they already had six authors. I hoped we thanked him, 
but I'm not sure. 

One other thing Devlin did. When I was looking at the 
spectrum of ruby I was studying how the line was dependent on 
temperature, and it didn't get nearly as narrow as you would 
expect to have at low temperatures. You'd think it should be 
very narrow because the lifetime was milliseconds so it should 
be a line width of kilocycles. But it wasn't, it was much 
wider than that. So I was looking at the thing with high 
resolution and Devlin was helping make the scans. 

He noticed a little bump on the side of the thing, and he 

insisted that that's real. 
you know. He said, "That's 

I thought oh, it was just noise, 
real." Of course, again I realized 
immediately that could be an isotope effect because there are 
several chromium isotopes. And indeed it was. Remeika made us 
samples of the separated chromium isotopes. Devlin was 
wonderful. He didn't really know the theory of the thing, but 
he had open eyes and he'd see things. 

Riess: To track some of these publication dates then-- 

Schawlow: Do you have my bibliography? If you don't, I should give you a 

Riess: The article for Physical Review that you and Charlie did came 
out in December of 1958. 

Schawlow: That's right. It was published very quickly. We submitted it 
in late July or early August of 1958. 

Riess: When you publish are there letters in response or is that not 
the kind of situation? 

Schawlow: Not usually. People can complain if there are mistakes in it, 
like you didn't give credit to somebody, something like that. 
But there was no response after that. The attitude of most 
people was they didn't think it would work and gave various 
reasons for it. But a few people believed in it, started out 


to try and make optical masers with various materials. And by 
the end of 1960 there were I think five different lasers. 

Riess: The Quantum Electronics conference [September 1959] must have 
been an exciting event in and of itself. 

Schawlow: Probably. Most of it was on microwave masers. I was so busy 
and so slow that I didn't go the first two days of it. I just 
stayed back at Bell Labs writing the paper because I didn't 
have time to do it before then. So I only went to the last day 
of the thing. And there weren't many people working on optical 
masers yet, but they sure were after that. 

Riess: Did Maiman pick up on it from being in the audience or from a 
later publication? 

Schawlow: He had been in the audience, but also there was a conference 
that Peter Franken sponsored on optical pumping at Ann Arbor. 
He called me up just a few days before the meeting and wanted 
me to preside at a session and give a talk. Well, there was no 
time to get official clearance for a talkthat was in '59 too, 
I think Maiman was there. But I did tell a little bit about 
these pair lines which were in the course of publication. I 
did suggest just that they'd be suitable for various kinds of 
masers without being specific. 

Riess: I'll be interested in the bibliography. 

Schawlow: If you want to take a moment's recess, I think I can start the 
computer printing it out. 

Pressure Results in Exhaustion 

Riess: It's clear that 1960 was a big year in your life. 

Schawlow: It really was. We had a lot of results. It's one of the 

reasons why I didn't try to build a laser myself--! should have 
--but I was finding so many interesting things in these 

Riess: You said something about thinking about the ruby lines and you 
couldn't get to sleep. 

Schawlow: No, the thing I couldn't get to sleep about was I wanted to 
know whether the laser produced a beam or not . 


Riess: Okay, right. But it made me wonder how good you are about 
leaving it behind when you come home? 

Schawlow: Pretty much in those days. I didn't really work at home very 

Riess: Did you go in on weekends? 

Schawlow: No. Things have changed at Bell Labs. There wasn't much 

pressure in those days. I think we felt that everybody was 
more or less equal. We didn't know what people were making. 
Later on they made a point of introducing what they called 
"octiles," where they were dividing everybody into categories 
and said they were going to adjust salaries accordingly. What 
I heard from others who were at Bell Labs later was that then 
the pressure sort of grew, and people were working night and 
day there. It wasn't that way when I was there. They did work 
hard during the day, but that was it. 

You couldn't help thinking about things sometimes. The 
particular time when I was sleepless was when the three of us-- 
Collins, Nelson, and myself--knew that there were a lot of 
things to try out. They did bring their laser down to my lab 
because I had the spectroscope and oscilloscope and so on. So 
we'd argue about what to do next, and it was at that point that 
I sort of felt that 1 just had to take over and check to see if 
there was a beam or not. And there was. 

Riess: Was Charlie still involved? 
Schawlow: Not very much. 

Riess: Was he still consulting at Bell Labs? 

Schawlow: Let me think. I'm trying to get the schedule of things. In 
1959 he took a position in Washington with the Institute for 
Defense Analyses [IDA]. After that, he couldn't consult. 
Columbia later asked me to come as a visiting associate 
professor during the academic year 1959-60 to help his students 
where I could and to teach some classes. 

Riess: Students who were working on maser experiments? 
Schawlow: Yes, that's right. 

Well, that was a horrible time for me. That was I guess in 
the winter of 1960 before any lasers had operated. It was 
horrible because I couldn't leave the stuff at Bell Labs. 


Devlin was still working, but he did flounder when I wasn't 
there. Things were not getting done. I would go in [to New 
York City], I don't know, three or four times a week, and I 
would come home every night and that was a long trip. 

I got sick. I got cold after cold, ended up with a fever 
around the end. I was supposed to give a talk in June, or 
July, at a meeting, and I had to cancel at the last minute 
because I had a fever of 103 or so. At this point the doctor 
finally gave me an antibiotic that took care of it. It was 
just sheer exhaustion, and I've learned since then that if I 
get overtired, I get sick. 

Riess: How did Aurelia respond to that? 

Schawlow: She was very good, but it must have been very hard for her 

because she had the three children by then. Of course, when I 
was home I'd do what I could. We did a lot of things with the 
family when I was home, and we were involved with the church, 
the nice young people's group that we were in. 

Riess: By "respond," I would expect a sort of outrage. 

Schawlow: No, she didn't push me to do anything. Then I think when I 

started getting offers in 1961--I was approached by a number of 
different universities--. 

Riess: Let's get back to the chronology. You had a Columbia spring 
semester, and that ended when summer came along? 

Schawlow: Yes. 

Riess: And then summer and fall you were back in the groove at Bell? 

Schawlow: Yes, I guess so. Now, what was I doing? Oh, I was still 
working on some of these solid state materials. 

We had a visitor from Japan, Satoru Sugano, a brilliant man 
and a wonderful person. He had already published papers on the 
theory of ruby before he came. I think he must have come in 
'59. It was before we published our work on the pair spectrum. 
So I think he probably was surprised when he saw that, but we 
did work on stressing ions and crystals, and he did some 
theoretical work on that. I was surprised when I went to an 
American Physical Society meeting and found he had been 
collaborating with two other people at Bell Labs too. He was 
just very productive. 

I just had a fax from him two days ago. He retiredthe 
Japanese style is they retire at sixty and usually take another 


job for five years as a dean or something like that at another 
place. And he did that. But he retired the second time a year 
or so ago. He's building a house in the mountains in central 
Japan, some town whose name he gave but which means nothing to 
me. But he also apparently inherited some money and is using 
that to set up a foundation to put on conferences in the fields 
he's been interested in. 

Publishing with Bell Labs--The Clad Rod Laser 





You've talked about publications. What kind of support did 
Bell Labs give you? Did they do the typing? 

Yes. They did do the typing. How did they do that? I forget 
whether there was a departmental secretary that did it or not. 
There must have been. They did have a typing pool, maybe 
that's where it was done. I don't remember. 

I was in a carpool around that time and there was a lady 
there who worked in the editorial branch who was supposed to 
straighten out the language of engineers in their reports. So 
I asked her to try and see what she could do with one of mine. 
She said I didn't need her help. 

No, I would say not. 
are clear. 

I think your papers, the ones I've read, 

Well, once I get the ideas clear, 
That's the hard part. 

it's not hard to say it. 

Was there a "publish or perish" feeling at Bell Labs? 

No, not really, although I felt that I obviously had to produce 

I think I was probably in danger of perishing before I got 
into this [maser work]. I don't think that I was very highly 
rated at Bell Labs at all. I think I mentioned that they made 
me the department safety representative and also asked me to 
supervise a technician who was running the helium liquefier 
which turned out to be a terrible headache. I worked hard to 
get him classified to a higher rating, which he really didn't 
deserve, but I finally managed to pull it off. But he didn't 
get enough of a raise, so he then filed a grievance with the 
union I think. 

Riess: Well, good that you got on to this. 


Schawlow: Yes. It's good that I got onto the optical stuff. The laser 
was obviously something important. They realized that right 

Riess: So the clad rod laser? 

Schawlow: That was something we did probably in the time you're talking 
about, probably the end of 1960. 

Riess: What does that mean, clad rod? 

Schawlow: A clad rod. It meant that the ruby rod was the core of a 

larger rod whose outside was clear sapphire. Now I'd heard 
that the Union Carbide people were making some of their 
crystals in a doughnut form, or like this, [draws] a disk. 
They would drop sapphire or ruby grains on the edge and melt 
them with a torch. And as this thing rotated [demonstrating on 
lid of a sugar bowl] it would grow radially like that. 

So I realized that they could grow one that had ruby at the 
core and then sapphire outside that. I also realized that if 
you look at the way the light goes in there, it's bent towards 
the axis; no matter what angle it comes in from the side it's 
refracted, because there's a high refractive index in ruby. It 
bends more towards the center, so that all the light over a big 
angle would come through this central core. Thus you get more 
efficient pumping and so get lower pumping power required. 

Riess: So essentially it's a sapphire-clad ruby rod. 

Schawlow: Yes, that's right. Ruby-clad with a sapphire outside. We got 
a patent on that, I think. But they were hard to make and they 
were more strained than the pure ruby rod because the sapphire 
has a slightly different crystal structure spacing than the 
ruby, so it didn't quite fit and that strained the material. 

An interesting thing was pointed out by Joe Giordmaine--he 
explained why it was the early ruby rods produced a good beam, 
even though they could get reflection off the sides. The 
reason was this business of the focusing of the light as it 
came in, so that it was more intense at the center than at the 
outside. So as you'd reach the threshold for laser oscillation 
along the axis of the rod, and not at the outside, and it would 
be absorbing at the outside. That's why light that went out to 
the side and was reflected wouldn't get amplified much. 

I think that may have been what inspired me to think that 
the clad rod, that here was the ruby and it was being focused, 
but some of it was being absorbed and therefore wasn't useful 


in the outer regions. So the idea was to have the same 
focusing effect without the absorption. 

Riess: What were the virtues of the clad rod laser? 

Schawlow: Lower pumping power. More ef f iciency--you collect the light 
more efficiently. It was fun thinking about it. It was the 
sort of thing, again, that people didn't believe at first. 

Riess: You like that, don't you? 

Schawlow: I do, yes. I think I've said before, if you have something 

that some people can't believe and say it's wrong, and others 
say it's obvious, then I feel I have something good. 

Time to Leave Bell Labs 

Riess: Fall of 1960. I wonder what was going on that convinced you 
that it was time to leave? 

Schawlow: I had a whole lot of different experiments going on that I was 
trying to do, a whole lot of ideas. I just couldn't do all the 
things I had in mind to do, so I felt it would be good to have 
students to work with me. That was the main reason, I think, 
intellectually. Also, I was getting annoyed at the jealousy 
that was apparent among some of the people at Bell. 

Riess: Did you approach Bell with what you wanted? 

Schawlow: No. 

Riess: You just knew that within the structure it wouldn't happen. 

Schawlow: Yes. Charlie ran into that too earlier. They encouraged his 
work on microwave spectroscopy, but they wouldn't give him 
another person to work on it. So I just kind of assumed that 
was all one could do. 

Now Ali Javan, who had the proposal for the helium neon 
[He-Ne laser], which was the first gas laser, did manage to get 
two others to work with him on it. Two very good people. So 
maybe some things could have been done, but I think that was 
the main reason. And then the question of Artie came up too: 
New Jersey was a terrible place for illness in those days. 

Riess: I want Artie not to be just brought in sideways. Maybe the 
next time we could start out by talking about that. 


Schawlow: Yes. It was a consideration, and in fact one of the reasons 
why I went to Stanford rather than somewhere else. 

Riess: How did you go about making yourself known, that you were 

Schawlow: Didn't have to. People would call me. I didn't apply for 
anything . 

Riess: What were the most appealing choices? Did you go to meetings 
and talk to people, or did you already know all the 

Schawlow: Indiana University invited me and I went and talked with them. 
It was attractive. Although it wasn't a great university, it 
was a good place and I think it would've been good. Professor 
Mitchell was the chairman, and he had worked earlier on 
resonance radiation and co-authored a book on it back in the 
thirties from which we got a lot of information. 

The University of Toronto came after me. That was, of 
course, attractive in some ways, but Aurelia didn't want to go 
there. She'd been to Toronto several times, and people 
there--. Well, she was a Southerner and Southerners, you know, 
you go to New York or somewhere they kind of twit you about the 
lynchings there and things back there. And you go to Toronto 
and they sort of come at you about the things that the United 
States government is doing that they don't like. So she felt 
that she just wouldn't be comfortable there, although if I'd 
really wanted to go, I think she would have gone anywhere I 
wanted. Certainly she didn't like the idea of going as far as 
California, but there were good reasons to go. 

I did get approached by Johns Hopkins and also Columbia, 
but I think that was after I'd accepted Stanford. 

Riess: Would you have to have brought your own money? 

Schawlow: No, I really didn't know what the things were going on there 

[at Stanford], but I sort of assumed there would be money like 
there was at Bell Labs and I went ahead and ordered stuff. And 
in fact the Microwave Laboratory at Stanford was well-funded. 
I knew I'd have to apply for some money of my own, but they set 
me up and get me equipment for things, some fairly expensive 

Riess: Did you talk about money with the other places? Indiana? 

Schawlow: No, I didn't discuss what money they could provide. I know I 

was used to--working at Bell Labs, well, sort of "money comes." 

Riess: And money was coming for science then? 

Schawlow: Yes. Actually it was beginning to decline slightly. 

Apparently in the late fifties it had really been awash with 
money and you could just get anything for any purpose. By then 
it was beginning to get a little tighter, but it wasn't bad. I 
got support from NASA first. 

Riess: What did it feel like to be out of Bell Labs? 

Schawlow: Well, nervous. I managed to get a one year leave of absence in 
case I wanted to come back, but I didn't really think I was 
going to. But you know, there were things I'd worry about-- 
like I had to teach, and I didn't know whether I could do a 
conscientious job of teaching and still have any time for 
research. Well, I guess I feel I've never had enough time for 
either of them. But I could do an adequate job, I think. But 
I could have been a better teacher if I hadn't had other 

The most productive time for experimental physicists is 
between ages thirty- five and forty, and those were good years 
for me. I was thirty-five in 1956 and forty in 1961, full of 
ideas and able to get a lot of them tried out, and some of them 
were working and other people were working on things I ' d 
started. Of course I was trying to follow everything that was 
going on in connection with lasers, which has long since become 
impossible. So it was an exciting time. 

Certainly when I heard about the announcement of Maiman's 
first laser, I was really excited because then I began to 
realize how important it was, because he'd got just a short 
pulse but peak power of kilowatts. And I'd been thinking of 
milliwatts. So this was much bigger than I had thought of. 

When this picture of Maiman appeared in the newspapers, he 
was holding a flashlamp, a pretty big flashlamp- -obviously a 
General Electric FT 524, because there weren't many flashlamps 
on the market at that time. He didn't say what he used and he 
didn't mention the rod, and the rod was obviously a few 
centimeters long, maybe five centimeters and about five 
millimeters in diameter, something like that. Just, as I say, 
what I'd been thinking of. 

But in fact, that wasn't what he used. He used a smaller 
lamp and a short, stubby crystal. I think it was this focusing 
effect that made his produce a beam. Well, the question of why 
he showed a different one [in the picture], one of his 
colleagues told me the reason was that when the photographer 
came to take the picture all of the lamps he'd actually used 


were broken. [laughs] He himself has testified, I think in a 
patent suit, that the photographer thought this was better 
looking, but I don't know. 

Riess: What was the patent suit? 

Schawlow: I don't know. He did get a narrow patent on ruby lasers, but 
the basic patent was ours, which was issued ridiculously early 
in 1960, March of 1960 and of course expired in '77. 

Riess: You had no control over that. 
Schawlow: No. 

We saw that picture and we recognized what it was, so we 
bought some FT 524 lamps. The advantage of that was that I was 
able to put a small vacuum jacket inside a glass finger, a 
Dewar vacuum flask, so I could cool my dark ruby rod to low 
temperatures and still get a powerful blast from it. That was 
one thing that made it easy both to check that the lines got 
sharper as you cooled the crystaleven the laser lines did-- 
and you could run the dark ruby pair line laser at liquid 
nitrogen even. 

Riess: We are looking at this picture from the IEEE article, July 

Schawlow: Well, that one we usedit's not easy to see in this copy, but 
we used a straight flash lamp and a reflector, an elliptic 
cylinder reflector. But in our earliest experiments we used 
the same sort of a Dewar that you see there, with a fairly 
narrow finger but it had to be big enough to contain a vacuum 
jacket. And we just put it down inside the flashlamp. 

Riess: This is the drawing of the Dewar. 

Schawlow: Yes. It shows it inside the cylindrical metal housing. I 
think they cropped that a little bit so that you can't see 
where the flashlamp is in the drawing, but the flashlamp would 
be off to one side in the cylinder. There's the cylinder- -the 
lamp would be over here somewhere and the light would be 
reflected from the inside of that cylindrical mirror. 

Riess: You do realize how simple this whole thing looks? 

Schawlow: That's the way I am. If I had known it was that easy--. I 
just couldn't think that anything that simple would work. 

Riess: Isn't it extraordinary? I don't know whether this is like a 
general principle of physics 



No, it's just the way I work, 
complicated things. 

I just don't have the mind to do 




Back to the first laser: now, a laser doesn't work until 
you get above the threshold where you have enough gain from 
excited atoms to overcome losses. Well, we had a very poor 
ruby rod, and we had a power supply, and a big lamp that was 
rated at 4,000 watt-seconds--that was the most you were 
supposed to put in it--or 4,000 joules. But it didn't lase at 
that. So I thought, "Well, what have we got to lose"--we 
turned up the power and at 4200 joules it started to lase. 
That same thing happened again once with one of my graduate 
students, but that's later. 

What do you learn from that? 

You learn that there's a threshold and you have to get over 
that threshold. It doesn't come up gradually. Well, there is 
a buildup close to it, but it's a sudden thing. If you're 
below the threshold, it isn't lasing; if you're above it, it 


A couple of stories you have told of going from doing things 
the way you're supposed to, slowly and meticulously, to 
blasting off, like when you were trying to-- 

Get those mirrors. 

Yes, right. 

Sometimes you have to be rough. 

Ah! That's what I wanteda quotable end line: "Sometimes you 
have to be rough." 

National Inventors Hall of Fame, 1996 
[Interview 5: October 30, 1996] II 

Schawlow: [Talking about recent trip to Akron, Ohio, to be inducted into 
the National Inventors Hall of Fame] By Thursday morning I had 
bad chest pains, and that turned out to be pleurisy. I had to 
sit up all that night because I couldn't find any position 


where I could lie down. But then, as you can see in that 
newspaper story, Dr. Forrest Bird treated me. 1 

Riess: And who is he? 

Schawlow: He's a member of the National Inventors Hall of Fame for 

inventing various respirators. He had one shipped in and he 
gave me a treatment and managed to get my lungs straightened 
out. Apparently pleurisy only lasts a few days anyway, but he 
got me breathing again pretty quickly. 

[indicating the respirator] The thing is worth $3600. Dr. 
Bird gave it to me, and that was because he is very grateful 
for inventing the laser, because his wife just had an operation 
for endometriosis with a laser. It's a pulsed respirator; it 
puts out pulses of air up to five times a second and about 
forty pounds per square inch. This is supposed to loosen up 
stuff in your lungs and so on. 

Riess: Quite a story, and quite a coincidence. 

Now, what is this videotape that you've given to me? 

Schawlow: That's quite a story too. Back in 1965 or 1966--the California 
Academy of Sciences had been sponsoring a program called 
"Science In Action" on educational tv, and this was near the 
end of their run. They had an independent producer, and they 
decided that they would do one on "the scientist," and they 
somehow picked me as the scientist. They came down to my lab 
and to my house, filmed me with my daughters. In that I talk a 
little about how I felt about physics and things that you are 
going to discuss today. 

One of my former post-docs called and urgently wanted a 
copy of that film. I could not find that videotape, and I'd 
sent the film to Cleveland to use in the material for the 
National Inventors Hall of Fame induction ceremony, and it 
hadn't come back. So the day before yesterday I called them in 
Cleveland. They said, "Oh, we sent that ten days ago, on 
October 10." They sent it to the university. They checked and 
found who had signed for it. Well, I asked the secretary. She 
hadn't seen it. Turned out it was down in the mail room, they 
had just left the box down there. 

I got it the day before yesterday and yesterday I made a 
copy and sent it to him. And I thought, well, maybe you would 

'See Akron Beacon Journal, September 23, 1996. 


be interested in that too. It's all about me and I do talk 
about how I felt about things in physics. 

Riess: You were the representative scientist. 

Schawlow: Yes, just the only one they did. Instead of talking about some 
particular discovery, they just talk about one scientist and 
see what he does, see what he's like, that sort of thing, which 
is a wonderful thing to have. 

The people in Cleveland had made a good VHS copy from the 
film, much better than I've been able to get made, so I made a 
duplicate of the thing. 

Riess: Thank you. Is that something you're able to do with your 
equipment here, you can make duplicates? 

Schawlow: Yes, well, I have two recorders so I can just take one from the 
other room and hook it up here. 

Riess: When you were in the hospital and surrounded by all the 

electronic monitors and gadgets, did you have some curiosity 
all that? 

Schawlow: I was pretty sick. Well, I admired some of the gadgets but I 

didn't really get into how they worked or anything like that in 

Laser Action in Ruby- -Physical Review Letters, Feb. 1. 1961 

Riess: Last time we had gotten to the point of your coming to 

Stanford, but I realize you haven't told about your 1961 
publication on laser action in ruby. That's the article that 
was published at the same time as an article by [I.] Wieder and 
[L.R.] Sarles. 

Schawlow: Okay. I had been rather simplistic in my approach to things. 
I had not really done any quantitative calculations, I just 
sort of went by instinct. I used Charlie's maser equation as a 
guide, but still--! saw that to get gain you had to have more 
atoms in the excited state than in the lower state. 

One substance that kind of fascinated me was ruby. I 
didn't know anything about solids but I had a feeling that 
well, it was sort of the Bell Labs culture, that anything you 
can do in a gas you can do better in a solid. Ruby was a 
crystal. There were samples around because they were using it 


for microwave masers, and so I thought I'd take a look at the 
spectrum of ruby. 

Trouble was that the atoms are all in the ground state when 
you startand although there's a good broad band that you can 
pump into with the green region, and then the ions all populate 
a level that fluoresces to the ground state and produce a red 
line actually, there are two very close together. But the 
trouble is that the atoms there are all in the ground state and 
you'd have to excite more than half of them before you'd get 
any gain. That didn't seem to me a practical sort of thing. 

But as we studied the spectrum of ruby we noticed that 
there were a lot of other lines there that were not accounted 
for by the theory. Fortunately we found out that they were due 
to pairs of chromium ions, because their proportion relative to 
the single ion lines got stronger as you made it more 
concentrated. George Devlin noticed that, actually in some 
crystals of gallium oxide with chromium, which is closely 
related to the aluminum oxide with chromium which is ruby. 

So we saw these lines were due to pairs and they were split 
by fairly large amounts by the exchange interaction between 
these chromium ion pairs which, in concentrated chromium oxide 
where it's all chromium and no aluminum, makes it anti- 
ferromagnetic. That is, the spins of adjacent neighbors are 
paired anti-parallel. Well, this meant that here was a system 
that did have lines that were spread out over a substantial 
regionand that meant that the energy levels were also split 
by several hundred wave numbers, which is equivalent to several 
hundred degrees temperature. 

So it occurred to me that by cooling that stuff to a low 
temperature--! didn't know how low you'd have to gothen you 
could empty some of these lower levels, and then you would have 
a much lower threshold. And all you had to do was get some 
atoms excited and you'd get gain. How much gain you'd need was 
hard to predict because the optical quality of these rubies is 
very poor. Just like, somebody said, Coke-bottle glassthey 
don't put Coke in bottles any more, I don't think, but anyway, 
it was not optical glass. 

I talked about that at the first quantum electronics 
conference. We published the results. I foolishly said that 
the R-line, which is the main line in rubies, was not suitable 
for optical maser action because you have to empty the ground 
state, but these ones would work. 

Well, I tried it very crudely. I got a rod polished and 
silvered, but I only had a twenty-five joule flashlamp. 


Actually it was a Strobotac for measuring rotational speeds, 
for motors or something like that. And that wasn't nearly 
enough, and nothing happened, so I just put it aside, which was 
foolish because Maiman then came along and showed that he could 
get more than half of the atoms excited and get laser action in 
ruby. That was the first laser. Then I helped Bob Collins and 
Don Nelson get their first ruby laser working: they copied more 
or less after what Maiman had published. We got that going 
around the beginning of July or so of 1960. We then set out to 
measure some of its properties, showing directionality and so 
on. We prepared our work, and that of Bond, Garrett, and 
Kaiser for a joint publication. We didn't use the word maser 
because we thought that Physical Review Letters had a ban on 
more maser articles, which they really weren't applying to 
optical masers. 

Then I remember asking the boss, "Should I try the dark 
ruby?" He said, "You owe it to yourself." That was Al 
Clogston. I got a big flash lamp and the same ruby rod. In 
the article about it I thanked Walter Bond for polishing the 
ends. It really was just one end that had cracked, the other 
end was still the original. And it did work. I got it working 
in November of 1960. In planning to publish these results I 
decided, "Well, if Physical Review Letters doesn't want 
articles on optical masers, I'm just going to send it to 
Physical Review." That is not as prestigious, but it's a very 
respectable journal. 

Our paper arrived on a day that they had a big snow storm, 
and a paper by [Irwin] Wieder and [Lynn R.) Sarles's also 
arrived on the same day. They reported that they had observed 
stimulated emission in dark ruby. I don't think they quite 
understood what the difference between stimulated emission and 
an optical maser was--I mean with the mirrors being essential. 
The editors felt that they had to treat them in the same way, 
and so our paper ended up in Physical Review Letters which we 
hadn't requested. 

Riess: What do you think the politics behind all that was? 

Schawlow: Politics? The editors are great people. Sam Goudsmit was a 

great scientist, and should have had a Nobel Prize. And Simon 
Pasternak was the associate editor. These are great physicists 
and they knew what they were doing, though they did make a 
mistake on Maiman 's original paper. By that time they realized 
they had made that mistake and didn't want to make another. So 
ours appeared in Physical Review Letters at the same time as 
Wieder and Sarles's paper. 


Riess: I guess I shouldn't have said politics. When I see the 

attention given to timing on all this I think, "Well, how is 

this important? This seems petty, this concern." And. yet it's 
not at all, is it? 

Schawlow: No, science is cumulative. It puts another building block, 
another brick, in the wall, so it's hard to tell. I think a 
lot of the stuff that gets into Physical Review Letters is not 
all that important, but they try to give things of general 
interest. It keeps getting fatter and fatter. Now it comes 
out every week. 

Riess: But that requires that you read so much more, it seems like 
there's not that much gain. 

Schawlow: Well, there of course are huge numbers of papers published in a 
lot of journals. But which one do people actually look at? I 
think Physical Review Letters is one that a lot of people do 
look at, even if they don't ever look at anything else. 

Riess: Were Sam Goudsmit and Si Pasternak doing science as well as 

Schawlow: I think by that time Goudsmit was semi-retired. I heard him 
talk about it. He got famous back in 1924. He and Uhlenbeck 
realized that the fine structure in atomic spectra could be 
accounted for if you assumed that the electron had a spin. 
Well, the concept of electron spin has been extremely important 
ever since then. 

This was a theoretical paper, but Sam--he really was an 
experimentalist at heart and he somehow got labelled as a 
theorist. He was at University of Michigan before the war and 
after the war he went to Brookhaven National Laboratory. He 
wanted to do experiments there, but they didn't want him to. 
He did one. He built a new kind of mass spectrograph, I think 
it was. But then they needed an editor for Physical Review and 
Physical Review Letters, and he took the job which is certainly 
a great service to the physics community. 

It grew very rapidly. In fact when I first joined the 
American Physical Society and for quite a few years afterwards, 
there was just a letters section in Physical Review; and then 
later they decided to publish Physical Review Letters as a 
separate journal. Now the Physical Review has grown so huge 
that hardly any individuals subscribe to it anymore. Libraries 
have to. The cost is very high, hundreds and hundreds of 


I used to subscribe to it, kept it up as long as I could, 
but it just got to be such a monstrous thing that I couldn't be 
bothered with it. So I gradually cut down to two sections, 
then one section, finally gave it up entirely. So anything 
published in Physical Review I just don't see unless somebody 
tells me about it. 

Riess: And the sections are very specific? 

Schawlow: There are five sections. There's one, I think it's atomic 

physicsatomic, molecular, and general physics. I forget what 
the others are: solid state, condensed matter, and nuclear. 
Particle physics. I think there's a theoretical one too. 

Riess: In editing the letters, is there a lot of back and forth with 
the authors to be really clear about what they're writing? 

Schawlow: Sometimes. Or sometimes they reject them. Sometimes the 

authors fight back and manage to persuade the editors to print 
their stuff after all. I know at least one case where the 
paper was rejected by several people, including me, as being 
not important enough to put in Physical Review Letters. But 
the author was a very determined guy and he got it in. 

Inventing Stuff 

Riess: Well, that all may be a footnote but it's interesting because 

publication and patent are both much more important than I ever 
would have thought in science. 

Schawlow: I have little use for patents because I had nothing much but 
trouble from them. Of course I didn't get any money from the 
laser patent. Bell Labs had given me a dollar for all patent 
rights when I joined the company. But they did support me for 
seven years before I filed any patent applications. 

However, just recently I was inducted into this National 
Inventors Hall of Fame, which is strictly based on patents. If 
I hadn't had that patent, I wouldn't have that. And now, in 
fact on Friday I have to go to San Jose to get the Ronald H. 
Brown American Innovator Award which comes from the Patent 
Office department of the Department of Commerce. This is a new 
award that they started last year. Again, just because I had 
that patent. 

Riess: And you're the first recipient. 


Schawlow: No, this is the second year. They are giving out seven this 
year. It was given in Washington on the fifteenth, but I was 
far too sick to go then. But the Commissioner of Patents, who 
is a Deputy Secretary of Commerce, or Assistant Secretary I 
guess, is giving a talk to the Patent Law Association in San 
Jose on Friday and asked me to go there and they'll present 
this thing to me. 

Riess: Is Charles Townes a member of the National Inventors Hall of 

Schawlow: Oh yes. He was in years and years ago. 

Riess: But aren't you identified as an inventor more than he is? 

Schawlow: No, oh heavens no. He invented the maser and co-invented the 

Riess: You have such an inventive turn of mind. 

Schawlow: Certainly not more than Charlie, who is really a very great 

scientist. But as I told the people in Akron, we experimental 
physicists are always inventing stuff. We have to invent the 
apparatus that will do the measurements we want to do, but 
often there are things that are not worth patenting. I gave an 
example, that in 1975 Ted Hansch and I published an article 
showing that it would be possible to cool atoms down to very, 
very low temperature free atomsby using laser light. 

Well, we didn't do it at the time because we were 
interested in hydrogen and there still isn't a suitable laser 
for cooling it. I didn't even think to mention it in my Nobel 
lecture. But in the eighties a number of people, including 
particularly Steve Chu who's now with us at Stanford, but was 
then at Bell Labs, showed that this would work and you could 
get down to a fraction of a degree absolute. Then things were 
fortunate. It turns out there are other mechanisms that we 
hadn't thought of that make it even better than we thought. 
And now they get down to micro Kelvins . 

Since then it's become possible to use these very slow cold 
atoms --they 're still free, but they're not moving very fast 
they can measure the acceleration of gravity more precisely 
than any other way, and that might be useful for prospecting. 
It's still too big an apparatus to take out in the field. 

Also, they can make an atomic gyroscope, which is probably 
better than any other. So these are inventions that may be 
worth patenting, though they're probably twenty years away from 
being useful. We saw that it was so far away from being useful 


for anything that there was no point in applying for a patent. 
If we had it would have expired by now. But it was an 

Riess: Yes. In order to apply for a patent you have to publish. 

Schawlow: You don't have to publish it in a paper, but you have to have-- 
in fact, one of the things I don't like about patents is that 
it's quite secret until the patent is issued, but you have to 
give them a description that will convince them that it will 
work, convince the patent examiner. 

Ours was what they call a constructive reduction to 
practice: that is, we described in detail how you would do it, 
and so they issued the patent. More normally, they would like 
to have a working model that shows that the principles of the 
invention actually work. 

Science Writers, Informing the Public 

Riess: Interesting. In the sequence of things, there was a story of 
you being asked to talk to the New York Times. You were being 
asked for comment about Mirek Stevenson. 

Schawlow: Oh yes. Stevenson had called me up the night before. 

Stevenson was a student of Townes's and had gone to work at 
IBM. It's quite an interesting story--! don't know whether I 
wrote that up before. He was very much interested in business; 
even as a graduate student he was making a lot of money in the 
stock market. He later started an investment fund. I don't 
know whether that's still going or not. At the time he had 
taken this job with IBM and was working with Peter Sorokin, who 
was a very brilliant experimental physicist and was a student 
of Bloembergen's at Harvard. 

I guess they heard--! 'm not sure if it was before Maiman 
did his stuff or after. I think it's probably before Maiman 
published his attainment of laser action. But Stevenson felt 
they should do this in a businesslike way and buy everything 
possible, don't take time to build it yourself. So he searched 
and found the biggest flash lamp on the market and he also 
found that they could buy the crystals that they wanted from a 
crystal growing company. So they quickly got laser action in 
divalent samarium and trivalent uranium. 

I think it was Stevenson, one of them called me up the 
night before it was officially announced. And I did find out 


that it was trivalent uranium and divalent samarium. So when 
the reporter called and asked me what I thought of, I said that 
it was good stuff and told him what it was so they got the 
story straight. 


Riess: That must be a challenge, the public need to know, and dealing 
with science writers and how to get things clear with them. 
Has science writing improved over the years? 

Schawlow: Well, there have always been some good ones. I think Lawrence 
of the New York Times was very good, very careful. The science 
writers were not bad. I think it's the regular reporters that 
have to deal with a story that really get things garbled 
sometimes. Even that has improved, I think. But I sort of 
came to the conclusion that whenever I saw some story in the 
newspaper about which I knew the facts, there was always 
something wrong with it. 

I really have to admire how science writers can jump from 
physics to biology to astronomy and everything. Of course, 
they tend to always want to fit it into a pattern. With lasers 
it's either a death ray or a cure for cancer or both. That's 
indeed the way it turned out, no matter what you told them, 
pretty much. 

Riess: You mean it's sort of the human interest. 

Schawlow: Well, yes, that's what they want. And these were old ideas. 

Of course, the death ray idea is much older than actual lasers. 
Buck Rogers in the 1930s comics strips and E.G. Wells' War of 
the Worlds--the martians had a sword of heat. Even back to 
Archimedes supposedly burning the sails of enemy ships with 
reflected sunlight. All these things. So this is an old idea. 
And as soon there were any lasers, that's what they jumped on, 
although the lasers that we had then were very primitive. 

I remember calculating that if you could deliver one joule, 
that's one watt second of energy, once a second, you could 
completely vaporize a two hundred pound manbut he'd have to 
stand there for two years. 

Riess: Now that's an image! [chuckles] 

Schawlow: I didn't think much of them as weapons, and in fact they're 
still not really usable as weapons. They've got some giant 
lasers that will fry things, but what they really want to do is 
melt missiles at five thousand miles away, and that takes an 


awful lot of power. It could be countered by putting a little 
more shielding or more decoys. 

Riess: When the newspaper calls, do you view it as an opportunity to 
clarify things or do you greet it with dread? 

Schawlow: I don't greet it with dread. I try to give them the story as I 
see it, and I don't worry too much about how it comes out. 

Post-Laser Atmosphere at Bell Labs 



Another event. What you refer to as "the first public 
demonstration of an operating laser" was at the Nerem 
electronics meeting. 1 

The Nerem meeting occurred in the fall of 1960. 
we had a laser, a big clumsy thing. 

By that time 

As soon as lasers came on the scene, the atmosphere changed 
at Bell Labs. First of all, there were a lot of people who 
wanted to talk to me whereas before in superconductivity I was 
pretty much all alone. But also there was some jealousy and 
secrecy. People weren't telling things that they were doing, 
even within the laboratory. 

I had been asked months before to give this talk at the 
Nerem meeting and I had agreed. But I had to circulate an 
abstract for approval. One of the other people at Bell Labs 
that had been involved in that combined paper about the 
properties of lasers said that all the authors should be 
consulted on this thing. Well, I got rather angry. This was 
something I had done myself and I could talk about stuff that 
they had published and give them some credit, but still the 
original thing was mine. 

I really was quite angry and I complained to Clogston. He 
said, "Let me take care of this." I heard no more about it. 

They'd had a press conference from Bell Labs before that, 
and again I had this feeling of jealousy. In fact, they 
arranged it so that I wasn't the first speaker. There were all 
six authors of that paper on the properties of lasers and I 
think they put me in third or fourth place there. I was 

1 p. 143 "From Maser to Laser," Arthur L. Schawlow, in Impact of Basic 
Research on Technology, Plenum Press, 1973. 


supposed to explain the principles of the thing and they tried 
to deemphasize me. Well, the newspaper wasn't fooled, 
[chuckle] But that's why I really began to think of leaving 
Bell Labs. 

Riess: Was Bell Labs trying to recast the invention in terms of being 
a kind of communications breakthrough? 

Schawlow: They did want to emphasize that all right. And these people, 
they'd all done something. But they wanted to feel their part 
was just as important as anybody else'swhich it wasn't. Mine 
had come first, and the whole thing wouldn't have been thought 
of if we hadn't done what we did. 

Riess: It's hard, as I sit here, to imagine you getting very angry. 

Schawlow: [laughs] I don't very often. But that really annoyed me. I 
said, "Well, if they want, I'll just talk about the theory and 
not about any of these results." 

Riess: In fact, you did have contacts with the newspapers and you 

could have gone public and really embarrassed them, I suppose. 

Schawlow: Well, I'm not that kind. 

Gordon Gould, and the Competitive Drive 

Schawlow: I always feel that it's better not to attack others but just to 
say my piece. Now of course, one thing that I really hate to 
mention is Gordon Gould. He's been a real thorn in the flesh. 
He got elected to this Inventors Hall of Fame years ago, but 
his forte was patents. Patent lawyers control this thing 
pretty much. 

He was a graduate student of Kusch's. He'd never finished 
his Ph.D. He was older than I am, a year older. But somehow 
he got wind of what we were doing and he started writing stuff 
in his notebook. Oh, some months after our patent was filed, 
he filed a patent applicationnearly a year after. There was 
interference, and fortunately both the patent office and later 
the courts decided that he hadn't shown conception of the ideas 
in sufficient detail to be acceptable. Also he hadn't shown 
diligence in reduction to practice. But his lawyers filed 

Riess: Diligence in reduction 
Schawlow: --to practice, yes. 

Riess: What is that expression? 

Schawlow: Well, it means either writing a detailed description that a 

person "skilled in the art" could duplicate, or actually making 


He went to work for TRG, and I think his agreement was that 
anything he had done before then was his, but anything after 
that was theirs. But he kept on adding to his notes for his 
own personal patent application. To give you an idea of how 
dirty they were, two things: I can't say how much was his and 
how much was his lawyers and backers , but the company that was 
sponsoring his patent stuff, after TRG, a company called Refac, 
I think, and then later Patlex, they got into trouble because 
they were doing insider trading when they heard that his patent 
was going to be issued. They bought some of their own stock. 

But worse than that, the patent office decided that he 
hadn't shown conception of the idea and also hadn't shown 
diligence in reducing to practice. Then they took it to 
courtat that time it was being sponsored by Control Data, 
which had bought TRG, and they had plenty of money for good 
lawyers. But the court--! think there were three judges, and 
they ruled unanimously that he had not shown conception of the 
idea. Two of the judges ruled that he hadn't shown diligence 
in reducing to practice. The other one said, "Well, since he 
hadn't shown the conception, we don't need to rule on that." 

Then they put out press releases that this had only been 
rejected on the narrow grounds of insufficient diligence in 
reducing to practice, which was just a plain lie. 

Later, to give you an idea of what they did that was really 
rotten, they went after a lot of little companies. They were 
very smart at managing. They bought off Bell Labs and General 
Motors, I think, who could have put up a real fight, by giving 
them a cheap license. 

You mean Control Data did? 

Schawlow: No, that was later. It was Patlex or Refac. It was after the 
Control Data time. I think Control Data just gave up on it 
after that point. 

They went after a little company in the San Francisco area 
and this guy was too poor to hire a good lawyers to defend it. 
But in court, the lawyer for Gould's side got up and said, "You 
wonder why this great inventor hasn't received the recognition 
he deserves. Well, his professor," meaning Charles Townes, 
"had witnessed his notebook of an idea for optically pumped 
maser and then later put it into his own papers." 



Riess : 



This was really a disgraceful lie. Because, first of all, 
Charlie Townes had this particularit was just for an 
optically pumped maser, not a microwave maser. And Charlie had 
this idea in his notebook several months before that. And this 
had come out in earlier patent litigation, so it was public 
record and yet they lied and made it sound as if he had stolen 
some of Gould's ideas. And you know, Charlie is the most 

honorable man you ever met. 
playing that they did. 

But that's the kind of dirty 

Then they scrambled around and looked at things that maybe 
we hadn't quite specifically mentionedwe didn't really try to 
think of things around. They threw out his patent application, 
but the court forced them to reinstate it. They had accused 
him of lack of candor, meaning he'd said different things in 
different cases. 

He got a patent finally on maser amplifiers, said that we 
had only shown an oscillator. Well, you can't make an 
oscillator without having an amplifier. An amplifier provides 
the gain and then you have some kind of feedback. So we 
certainly had amplifiers. But then they tried to collect 
royalties on any laser. They said, "Well, it has an amplifier 
and we have a patent on the amplifier." 

It an extraordinary story because it's so singular, 
hear stories of this kind of greed and duplicity. 

You don't 


Well, this outfit had apparently done something similar in 
ultrasonic testing. 

Anyway, he did get a patent on gas lasers and I don't know 
just what he had that based on. They collected a lot of 
royalties on that. 

But do you put it to the company, Pat lex, or is it Gould's 
hysterical approach? 

Hysterical is not the word. But yes, I think he had a lot to 
do with it. Although the lawyers, at one point, boasted that 
Gould had invented the laser but they had invented the patent. 
And his patents were issued many years after. Of course, that 
was good because by that time there was a lot of business to 
collect from. But he just maneuvered and made it not 
worthwhile for anybody to fight it even though it really could 
have been fought. 

No, hysterical is not the word. 

Schawlow: Devious. 

Riess: Yes. Science is relatively free of that sort of thing. 

Schawlow: This wasn't science. We're talking about money and inventions 
and technology. I noticed a big difference as soon as this 
thing got to be something that somebody might make money on. 
Oh, I hate to put this stuff in print. 

Riess: I would have brought Gould up because you write that TRG 

invited you to give a talk there. You say, "...we exchanged 
ideas about work on spectroscopy of rare earth ions of the sort 
that might be useful for optical masers. nl 

Schawlow: Yes. Then they were still fairly open. 

Also, in 1959 there was a conference that Peter Franken 
sponsored on optical pumping at Ann Arbor. He called me up 
just a week before and wanted me to come preside at a session 
and give a talk. I didn't have time to get clearance from Bell 
Labs, so I spoke rather obliquely. 

Again, Gould was there, and he said, "We have six different 
kinds of materials and a number of different structures, but 

unfortunately this is all classified, 
of it." [laughter] 

I can't talk about most 


For the Shawanga Lodge conference in September 1959 Charlie 
said, "Well, let's not fight in front of the Russians. Try and 
say something nice about Gould." I did mention his idea of 
using a scatterer instead of a mirror, which is okay but not 
very important. 

Was this the time that the Russians that shared the prize with 
Townes were here? 

Schawlow: Yes, they came to this conference in '59, the first quantum 
electronics conference. That's the first time I met them. 

But at this one in Ann Arbor I did tell about the ion pairs 
and said they'd be useful for various kinds of masers without 
indicating that I meant optical masers. Maiman was there and I 
think he got some ideas from that. But I couldn't resist- 
after Gould gave his talk, I said, "Well, your laser really is 
more of an oscillator than an amplifier, so we should change 
the "a" to an "o" in your entry into the optical maser race, 

'ibid, p. 13A 


Oh, I'd never seen anybody like that and I hope I don't. 
But certainly in science that doesn't happen. Particularly 
high energy physics where there are rather unique sharply 
defined problems, there's some very dirty work goes on trying 
to get publication before the other guy does. They have to 
make sure enough that they have the results, but not wait too 
long or other people will do it. 

This book, Nobel Dreams, about Carlo Rubbia, who did get a 
Nobel Prize- -when they were working on this thing that got them 
the Nobel Prize, there was another group at CERN working on the 
same thing. He met the leader of this other group and said, 
"Well, we must be careful not to publish prematurely. Make 
sure we really have a result." Meanwhile he had a courier 
taking the manuscript to Physics Letters in Amsterdam. But 
I've never had anything like that. 

Riess: It's one thing if it has to do with real greed and money, I 
suppose that's not okay. But if it has to do with academic 
competitiveness, you're all in an academic world where it's 
kind of dog eat dog? 

Schawlow: Well, not for me, fortunately. But I think in high energy 

physics it is that way. And in his case he got a Nobel Prize 
and the other guy didn't. And that's very valuable, even apart 
from the money involved. He gets all sorts of prestige. 

In my world it's not that way. I have always said, "If 
anybody wants to do anything that I'm thinking of, okay. I 
have a lot more ideas that people don't think are worth 
following up." As I've told you before, I'm really not a 
competitive person at all. I'll go out of my way to avoid 
competition. So it's a different world, different people. 

Riess: Well, then the university is different from Bell Labs. 

Schawlow: Bell Labs usually was not that way. It was only when people 

smelled something that was really important that they began to 
fight for it. Mostly they were very open and friendly. 

In fact, what it took me a long while to realize at Bell 
Labs is that they wanted to cover a lot of different topics, to 
keep an eye--the purpose of their research, they claimed, was 
just so that they would have a good view of all the frontiers 
of any science that was related to their technology. So they'd 
have just one or two people working on each area, so there were 
a lot of lonely people around there. If you wanted some help 
on something, you'd go to them, and they could drop what they 
were doing and help you. It took me a long time to find that, 


about five years, but certainly that's one way that Bell Labs 
works so well. 

Typically, a person gets an idea: he goes to crystal-grower 
A, gets some crystals; goes to somebody who has equipment, B 
and C; and then takes the results to theorist D. And you come 
up with a paper with a lot of names on it. They think, "Oh, 
Bell Labs has put a big group on that," whereas by that time 
they're probably not even speaking to each other. So it was a 
very good environment that way; it didn't seem competitive at 

They tried to make it more competitive. About the time I 
was leaving they started clearly rating people in octiles, 
giving bigger raises. When I was there people worked hard, but 
they didn't work long. There was not a lot of this all-night 
stuff which I gather there was in later years. 

As you'll see in that movie [video], I really feltthere 
were times I really desperately wanted to get the answers to 
things, really wanted to know. But I had to learn to be 
patient. When you have to work through studentsand some of 
them are awfully slow you try and help them, but it just 
didn't happen very fast. 

Riess: So you become more teacher than physicist. 

Schawlow: Yes. Well, more than hands-on. I didn't do very many 

experiments myself, at all, which is probably a good thing 
because I am quite clumsy. 



Riess: You were at Stanford in September 1961. In the negotiations 

for the Stanford job, did you have your NASA support? How did 
that work? 

Schawlow: No, I didn't. It was later. [laughs] Actually I was a little 
naive. They did have quite a lot of money. They had Joint 
Service contracts here, and I just kind of assumed that they 
would take care of me and went ahead and ordered stuff. 

I got the NASA contract after I'd been here a few months, 
I've forgotten just how long, and they supported me until they 
ran into hard times in the late sixties. And I guess I had to 
admit that my stuff wasn't very closely related to their 
missions. Fortunately, at that time NSF was growing and I 
managed to get onto NSF. I had some support from the Navy all 
along, and even a small grant from the Army Research Office. 
But they, again, ran into financial difficulties and dropped 

Riess: How did you get the NASA money? Did you know people there? 

Schawlow: No I didn't. I don't remember, tell the truth. I didn't know 
anybody there. But- -gosh, I can't remember, somebody must have 
suggested that I apply to NASA. I guess I talked with one of 
their program officers. 

I'm pretty naive. I didn't know much about how one got 
money for research, but as I say, they had this Joint Services 
contract. Money was still pretty plentiful then. Ever since 
then it's been getting harder and harder to get. 


The Department , Plain and Applied 

Riess: How about describing the department when you got here, who the 
other folks were and how you fit into it all. 

Schawlow: You talk about negotiationsabout the only two things that I 
had to make clear were, one, that I wouldn't come unless I got 
a full professorship. I was forty by that time and I didn't 
want to worry about having to get promoted. And there was no 
problem about that, they said okay. 

The other thing was that at that time the department had in 
it a number of professors who had the title of "professor of 
applied physics and electrical engineering." Their salaries 
were split between the university and their research contracts. 
The regular physics professors all had insisted over the dead 
bodies of the administration that they had to be paid full- 
time, and they were not going to charge any of their salaries 
to contracts. Because they foresaw what happened later, that 
when money got scarce some people lost their contracts, and the 
university would have to find some way to pick up their 

I said I didn't want to be in applied physics and 
engineering, I wanted to be just plain physicist, and there was 
no problem with that. 

It was a nice little department really, the smallest of the 
good physics departments, I think, by a lot, I think they had 
maybe fifteen permanent members, about five or so assistant 
professors. But they were a brilliant group. Leonard Schiff 
was the chairman, and had been for years. He was a theoretical 
physicist, but he was a very good chairman and very democratic. 
He kept things going nicely and was good at raising money for 
his own research. 

They had raised a lot of money. They had a lot of money 
from the royalties from the klystron patents. The klystron had 
been invented at Stanford by the Varian brothers, and they had 
gotten money from the Varian Associates. Both the Varians had 
died, but Mrs. Russell Varian gave money, as did the National 
Science Foundation. They were able to put up a physics building 
when the physics department had raised all the money. 

Riess: The Varians taught here? 
Schawlow: No. 


Russell had gotten a degree at Stanford. I don't know 
whether he had a master's degree or not. Russell apparently 
was brilliant, but as Leonard Schiff once described, he thought 
in a way in which logic was only a special case, [laughter] 
They had given him and his brother Sigurd, who was an airplane 
pilotthey were trying to do something to prevent airplane 
accidents and one of them had the idea for this klystron tube, 
which is a way of generating microwavesand they gave them a 
little space in the physics building, which was the old physics 
corner of the quadrangle. I don't know if they gave them money 
or not, certainly not much. There they built the first 

During the war klystrons became important and the Varians 
and several others who were later part of the applied physics 
department Ed Ginzton and Marvin Chodorow they went to the 
Sperry Gyroscope Company--! guess Chodorow hadn't been at 
Stanford before thenand worked on klystrons during the war. 
After the war, the Varians started this Varian Associates to 
make klystrons. 

Riess: Was there any question that Stanford owned this patent? 

Schawlow: I don't know the details, but these patents were worth several 
million dollars. They'd been obtained by Chodorow, Ginzton, 
and their associates. 

There are a number of threads here I have to tie up. 
Shortly after I came I think Leonard Schiff got tired of 
managing applied physics which was funded differently. 


Schawlow: There was a lot of pressure to add more positions in applied 
physics because it was cheap. Only a quarter of it came from 
the School of the Humanities and Sciences, and the rest came 
from engineering and government contracts. He really didn't 
want to build up too much in that , have it overbalance the 
department, so he pushed them into starting a separate applied 
physics department. It has done very well, it's a very strong 
department. Actually it's hard to tell, some of the things 
they do there are quite applied; some of the things could very 
well be pure physics. 

Riess: So there's an applied physics department plus a physics 

Schawlow: Yes. And the physics department does all the undergraduate 

teaching, which I think is in a way not so good. It meant that 
we all had to do a lot of undergraduate teaching, whereas they 


could just teach graduate courses in their specialties. I 
taught very few graduate courses and I could 've learned a lot 
more if I had had more time to work on that sort of thing. But 
after a while they made the point that these klystron royalties 
really had come from the people in the applied physics and not 
from the physics people, so we had to give up our interest in 
them. By that time they were nearly expiring. 

Felix Bloch, Robert Hofstadter, and Bill Fairbank 

Schawlow: Now, coming back to the physics department, the outstanding 

person in the department at that time was Felix Bloch, who had 
made a brilliant thesis in 1928 in which he set forth the 
quantum mechanical understanding of how metals conduct 
electricity. This really led to all the work on 
semiconductors, which in turn led to things like transistors 
and integrated circuits. 

He had come as a refugee in 1933. He was Swiss, but he was 
Jewish, and just felt it was better to get to a safer place. 
He said he was visiting in Copenhagen, at Niels Bohr's 
institute, when he got a cable from somebody named David 
Webster offering him an assistant professorship at Stanford. 
Apparently, this came up because I think the Rockefeller 
Foundation had made up lists of brilliant European physicists 
who might be refugees. He had never heard of Stanford and he 
asked various people about it. Some of them had been there. I 
think it was Pauli who said, "Jah, it was on the West Coast and 
he had been there, and there was another university nearby and 
they steal each other's ax." [chuckles] 

Well, he came there, and Enrico Fermi, who was also both a 
theorist and experimentalist, said to him, "You should do 
experiments. They're fun." So he teamed up with Luis Alvarez 
and they made a measurement of the magnetic moment of the 
neutron, which was a brilliant experiment, and that was in the 
late thirties. I think they did the actual experiment at 
Berkeley, but I think he prepared some of the equipment. 

Then after the war he started to look for nuclear magnetic 
resonance, or nuclear magnetic induction was the way he did it, 
and they did discover it in '46, I think, just about the same 
time Ed Purcell and his group at Harvard also discovered it. 
They shared the Nobel Prize in 1952, I believe. 

It became apparent--. Well, I'll tell you a little more. 
Bloch told me they used a big permanent magnet in their early 



experiments, and they had to make the magnetic field very 
uniform, so they put little iron shims on the face at various 
places to even out the irregularities in the magnetic field. 

He said they measured ethyl alcohol, CH 3 OH, and that he 
found that the relaxation time was quite long. That meant that 
the spectral lines should be very sharp and the magnet was too 
crude to see that. So he said, "I just want to see a line that 
sharp," and he kept pushing on his people to shim the magnet 
better and make it more uniform. When they did they not only 
saw a sharp line, but there were several lines. This was a 
chemical shift due to the hydrogen being in different places -- 
some of them in the CH 3 would be one kind and the OH would be a 
different one. 

So this was the beginning of chemical shifts , and it soon 
became apparent that magnetic resonance could be important for 
chemistry. Varian Associates therefore decided they would 
manufacture magnetic resonance equipment commercially. They 
did and they sold a lot of them. 

That's a story about the beginning of industry down here. 

Of course, [Frederick] Terman had pushed various people into 
starting companies, Hewlett-Packard particularly, and had 
gotten Stanford to set aside this land for the Stanford 
Industrial Park. 


Anyway, Bloch was there, back to doing theoretical work; 
after he got his Nobel Prize he gave up experimenting. 

Also Robert Hofstadter, who had done brilliant work--. 
When I came out here for interviews in the spring of 1961--I 
was very impressed by what he'd done and he was very friendly- 
he invited me to go salmon fishing with him on one of these 
boats out of San Francisco. Fortunately he then got the Nobel 
Prize and I never heard any more about that, [laughter] I'm 
sure I would have been very seasick. He was a nice guy, and 
unfortunately died a few years ago. 

Then Bill Fairbank had just discovered that magnetic flux 
in a superconducting ring was quantized. And that was a major 

Now say that again. 

If you have a ring of superconductor, the current will keep 
going forever and it'll hold whatever magnetic flux was in 
there. But he found that it came in quanta. The value was 
hc/2e: people had predicted this might happen, but the "2" they 
didn't predict. This was one of the things that showed that 


the electrons in a superconductor are paired, they act as 
pairs. This later helped lead to the theory by [J.] Bardeen, 
[L.J Cooper, and [J.R.] Schrieffer. 

Well, Bill should have had a Nobel Prize for that, but also 
apparently he delayed in publishing to make sure, and a German 
named Nabauer published similar results about the same time. 
Then Nabauer died, and I think because Nabauer wasn't alive to 
get the prize, I think that may have had something to do with 
the fact that he [Bill] didn't get it. He never did. 

Fairbank then went on to do some grandiose experiments. 
People said about him that he would find an experiment where 
they needed to improve sensitivity by ten orders of magnitude 
to do it and he'd get nine. [chuckles] Some of them didn't 
work, but he did spark the construction of the superconducting 
accelerator, and also the search for a superconducting 
gyroscope to test general relativity- -which is still going on, 
they still haven't flown it. It's supposed to have a space 
flight sometime in the next few years, but the people have been 
working on it some of them for thirty years . 

[knock on door, pause] 

Riess: We were talking about the department--. 

Schawlow: Felix Bloch and Nabauer and Fairbank. 

It was a wonderful little department. 
Riess: What about Panofsky? You didn't mention him. 

Schawlow: No. Panofsky had just decided that he would leave the 

department and head up the Stanford Linear Accelerator Center. 
He- -well, he tried to pull a few fast things on us. He wanted 
to have professors there and said they'd Just be research 
professors. Then he started demanding they should be allowed 
to teach. 


Schawlow: There was a good bit of friction between the physics department 
and the linear accelerator center. Finally, they managed to 
get President [Wallace] Sterling to assign teaching to the 
physics department and SLAC professors could teach by 
invitation, and we have always invited a few to teach. 


Riess: He wanted to get his staff on salaries. 
Schawlow: Yes, partly that, instead of just being paid by the contract. 

Well, they have a large number of professors. We were 
afraid we'd be swamped if they could do everythingthere "d 
been a lot of fighting in the years just before I came as to 
whether they would add a lot of people in the physics 
department or not. Bloch particularly didn't want to have the 
thing overbalanced by high energy physics. 

Riess: So they have professorial rank and are only doing experimental 

Schawlow: Or theoretical, yes. There are about twenty of them, something 
like thatat least as many as there are in the physics 
department. They've done well. They've got three Nobel 
Prizes, so it's been a success. 

Again, I had the feeling that, as with the applied physics 
people, they just wanted to teach the advanced courses and make 
us teach the freshman stuff. And really, that's the way it 
worked out, actually, they did teach mostly advanced courses. 
That's what I was afraid of when I came, but I just sort of got 
reconciled to it. It wasn't such a good thing. 

We had to establish that the physics department's duty was 
teaching. If we didn't have this duty, we wouldn't get any 
staff. These other people are cheap, and the university would 
rather hire them than get another person in physics. But if 
the physics department has courses that have to be taught then 
they have to give us some staffing. The physics department 
didn't grow through the sixties at all, whereas in many 
universities it expanded enormously. 

Riess: Stanford, in a way, really has three departments of physics 

Schawlow: Some people put it that way and say we should somehow 

rationalize them. But yes, there are three places where 
physics is being done. Stanford is wonderfully disorderly. 
There 're good physicists in electrical engineering and material 
science and so on, and students can do theses with them. Or in 
chemistry good physical chemists are quite good at physics. 
So it's not hard for a student in physics to get a Ph.D. in 
physics supervised by a professor from another department. 

Riess: And that's not good? 


Schawlow: No, that's all right. It means, of course, that we again have 
to do the preparatory work and support them the first year or 

To tell the truth, it used to be at first that the 
microwave lab was a place that we could dump the students who 
were not awfully good. They might be good at experiments but 
they weren't very strong theoretically. Now that isn't true 
anymore. They admit their own students and they get very good 
students, but sometimes some of them come over and do theses in 
physics. I had a student who was in electrical engineering do 
a thesis under me. So going back and forth is not bad. And 
physics has so much affected technology in the last generation 
or so that it's very reasonable that these places had to have 
their own physicists. 

Riess: What about Sidney Drell? 

Schawlow: Drell had been a professor at Stanford. He went on a 

sabbatical when I came, and when he came back he just decided 
he was going to go to SLAG so he never really did quite come 
back. It's too bad. He was a good teacher as well as a very 
good theoretical physicist. But he sort of--well, he just sort 
of treated the department with contempt. What really mattered 
was just SLAC. So I had very little to do with them. 

No, I sort of felt that I had come a long way, going 
across the continent where I'd never been much, in order that I 
could do research and teaching. While these people just sort 
of had it easy. They could do all the research they felt like 
doing, and teach when they felt like it. 

Riess: Others who were in your position must have felt somewhat the 
same way. It must have been a-- 

Schawlow: I think so, yes. 

Riess: --gnawing debate all the time. 

Schawlow: Yes, it was rather unpleasant. 

George Pake had been here before I came, and he wanted the 
physics department to start splitting salaries and build up a 
big solid state group to balance the high energy physics. But 
people like Bloch prevented that. He [Pake] left then. He 
became provost of Washington University, where he had been a 
professor before. That's Washington University in St. Louis. 
He later was the first head of the Xerox-Palo Alto Research 


Fortunately those fights were sort of coming to an end by 
the time I arrived, but there were still problems getting SLAG 
in its proper place. I went over and saw Panofsky when I came. 
It was clear that he felt he had the backing of Terman who was 
the provost, and that they were just going to do whatever they 
wanted to do. He was not at all interested in trying to find a 
mutually agreeable solution. 

Riess: What did you go over to propose? 

Schawlow: Well, to see what could be worked out, you know. As the status 
of people at SLAC and--. Well, it was apparent by then that he 
had gotten permission to have professors there. He was claiming 
that well, professors are professors and he can teach when he 
wants to teach. 

Riess: Oh I thought perhaps you were going over to propose something 
that was of an experimental nature. 

Schawlow: No. Just try to find a better relationship. 

Riess: Terman, as provost, was more involved than Sterling? 

Schawlow: Well, yes. 

Riess: Adjudicating all this. 

Schawlow: Well, we had to go over his head and go to Sterling finally to 
get it settled. But Terman was an empire builder, you know, 
and he had gotten a lot of government-sponsored research and so 
on. He was pushing expansion of that area. He was an 

Riess: He wasn't a physicist, was he? 

Schawlow: No, he was an electrical engineer. But he was provost, which 
is sort of the chief academic officer. 

Riess: Provost for the entire university not just a school. 

Schawlow: Yes, yes, the entire university. But Sterling was president. 

He was a very good president. He presided over the building up 
of Stanford and raising standards. I think it was under his 
presidency that it really became a great university, although 
it had always had some respectability. 

Riess: Then there was the other university on the other side of the 

Schawlow: Oh, I've heard there was one there. [laughing] 


Riess: Was there always the threat that one might defect to the other 

Schawlow: No, there was I think a gentleman's agreement that they didn't 
raid each other. I don't think that's in effect anymore, but 
it really happens very rarely. No, but there are other places 
in the country where one could defect. 

Riess: If you went to visit Panofsky in the beginning, it's clear that 
you saw what the situation was very early. But you decided 
that you could live with it. 

Schawlow: Well, we fought some to make sure that teaching was our 

business, at least, and that they didn't have authority to 
teach separately. I was on that side but it was a pretty 
serious fight. I understood the issues very clearly. Bloch 
and I were in complete agreement at that point. 

The Big Picture: Teaching, Labs. Students, Postdocs 

Riess: But the fight to teach some of the upper division courses? 

Schawlow: Well, we really earned our living by teaching the introductory 
courses, because those were the big ones with hundreds of 
students in them, and that had to be done. Somebody had to do 
it. We had a small department. 

In fact we had a very good traditionstarted or continued 
by Leonard Schiff--that the introductory courses were taught by 
senior faculty. They asked me after I'd been there a few 
months if I would teach Physics 21, which was Mechanics and 
Heat for pre-medical students, without calculus. It was really 
no more than a decent high school physics course. Well, I 
might have been insulted except that Bill Fairbank was teaching 
the second quarter of the Physics 20 series and Hofstadter was 
teaching the third. With that company, it's an honor to teach. 

Riess: That's interesting. Stanford could certainly say that our best 
minds are teaching our students. 

Schawlow: Certainly in physics. They had trouble in other departments. 

I heard complaints that economics was having a lot of part-time 
teachers teach the introductory courses while the professors 
were all busy consulting. 







You say that the loss to you in not teaching the upper division 
or graduate classes is that you don't get a chance to get back 
into that material? 

That's right. I could have learned a lot of stuff. I would 
have been forced to learn more advanced topics which I never 
did learn. 

Why are they things you didn't know? 

Oh, there's a lot I don't know. I'm not very good at 
mathematical stuff, as a physicist I'm really not awfully good. 
Compared to the man on the street I'm pretty good, but I just 
hadn't studied a lot of the advanced theory. And of course, 
stuff was coming out so fast in the laser field, that if I had 
been teaching it I could have learned more things, perhaps 
gotten ideas from it. 

I did teach a one quarter course in spectroscopy and 
quantum electronics in alternate years for a few years. Then 
after Ted Hansch came, he sort of took that over. 

I should think that would be one of the reasons they wanted 
you, was just because of this. 

Yes, you'd think so, but it didn't work out that way. But I 
did have a lot of graduate students. I built up very quickly. 
I remember telling one of them sometime that I had ten graduate 
students and never given a Ph.D. But then they started coming 
out the pipeline and my students mostly finished degrees in 
reasonable time. There were one or two that were hard to drag 

I had a lot of ideas, and I couldn't do them with my own two 
hands. I wanted students to work on some of these ideas and 
that worked pretty well at Stanford. 

Well now, you asked about how I raised money [referring to 
conversation during pause]. I was never very aggressive about 
that. I guess I would hear that a certain agency had some 
money and would take applications, and I talked with somebody 
there and applied for it. 

But I was careful not to get overcommitted. I didn't want 
to commit to doing something I didn't want to do. I would 
mostly only take money that left me pretty free to do whatever 
I wanted, because generally whatever I proposed didn't work 
out, usually there was something wrong with it. And it's the 
things that I hadn't proposed that workedyou get an idea and 







say, "Oh hey, let's try this." Really, that's the way it is 
with me. I'm not a good planner. 

What did you propose to NASA? 

Well, I think just general work on spectroscopy and quantum 

You weren't proposing or developing the laser in six different 

No, no. I didn't do very much on lasers then, it was mostly on 
materials related to laser materials, trying to get at the 

I remember one of the things that we did early. We had 
observed these pair lines of chromium in aluminum oxide. They 
had been known fifty years before, but not understood at all 
what they were. But since we knew they were pairs, and you 
could look at the crystal structure and you could see you could 
have pairs in different directionsa pair along the symmetry 
axis, or off in the side direction, or another side direction, 
and we wanted to find out which lines belonged to which pairs . 

So I had a student, Linn Mollenauer, working at applying 
stress to the crystals in different directions, seeing how the 
lines shift and which ones shifted the most. If you press 
directly along the axis of that pair it would shift more than 
if it was perpendicular to it. So he did some work of that 
kind, which was, as I say, related to laser materials but not 
really on them. 

These were things that had been in your mind when you had been 
at Bell Labs? 

Yes. And others, of course, came up as we worked. 

What does it mean to put together a lab? 
did you have? 

What kind of a space 

I was very, very fortunate. At first I was over in what was 
then called the Microwave laboratory. It's now called the 
Ginzton Laboratory. I just had a couple of rooms there. But 
then the new physics building opened and I think I had ten 
rooms, I had most of the second floor, and so I was able to 
expand fairly rapidly. There was enough money to buy basic 
equipment, but I never really had quite enough money. 


I had very few postdocs because I would rather spend the 
money on students and equipment and only sort of accidentally 
got postdocs if somebody came along. Actually I turned down 
one very good man in the late sixties, I think '68, a man named 
Richard Slusher. He was getting his Ph.D. at Berkeley and he 
had an NSF postdoctoral fellowship. I told him I didn't think 
we had a very good place, we were very short of money and 
space. So he went to Bell Labs and has done very well there. 

Riess: I thought postdocs did come with their own money, so why would 
you ever turn one down? 

Schawlow: Mostly not, mostly not. Mostly you have to pay them, and you 
have to pay them more than you pay students. So I didn't get 
many. Mostly you pay them from contracts, and I had fewer than 
most programs do. 

In 1970 I got this letter from Peter Toschek in Germany 
asking if I could take a young man who had done his thesis with 
him. Actually, they were sort of partners because Toschek was 
just learning about lasers then too. Well, I wrote back, said 
that I didn't have any money. He said, "Would you take him if 
he got a NATO fellowship?" 

I said, rather reluctantly, "Oh, all right." And it turned 
out to be Ted Hansch, who was absolutely brilliant. We saw 
that quickly and managed to find another hundred dollars a 
month for him somehow. Fortunately, about then we got an 
equipment grant from NSF and we were able to get some new 
equipment. Wonderful things happened from then on. 

But in the sixties there was one assistant professor, Peter 
Scott, that I sort of inherited. Pake had hired him. He'd 
gone off to England, to Oxford, for a postdoctoral year, but 
they had this commitment to give him an assistant professor 
ship. He worked with our group, but he did teach some too. He 
is now a professor at the University of California, Santa Cruz. 

Bill Yen, from Washington University, worked with us about 
then. Yen is now a professor at the University of Georgia. 
Warren Moos, who was here at about the same time as research 
associate and acting assistant professor, is a professor at 
Johns Hopkins University. 

We did have another visiting scientist, Serge Haroche, who 
came in 1972. He came from the Ecole Normale in Paris and was 
very brilliant. He did beautiful physics research here, and 
also after he returned to Paris where he is now the head of the 
physics department of the Ecole Normale. 


In 1977 James Lawler came from the University of Wisconsin. 
He also had good independent ideas and the ability to carry 
them out. He returned to Wisconsin and is a professor there. 
He has received several awards for his research, particularly 
in applying laser spectroscopic methods to study gas plasmas. 

Then in 1981, when I was president of the American Physical 
Society, the society provided half support for a postdoctoral 
researcher. Steven Rand, who had already been a postdoctoral 
researcher at the IBM Laboratory in San Jose, came and worked 
on spectroscopy of ions in crystals with laser excitation. He 
was enormously helpful, particularly in organizing the agenda 
for the November meeting of the American Physical Society when 
I was so occupied getting ready for the Nobel prize activities. 
He is now a professor at the University of Michigan. 

Riess: You mentioned having a couple of rooms. The experiments you 
were doing could be done in a regular room? 

Schawlow: That's right. We used one of them for kind of a workshop and 
others for labwork. After Hansch came, he gradually took over 
more and more of the space. 

Riess: Our discussion of Stanford has started out with a run-down of 
how it's divided up and all of that. And you said you went to 
visit Panofsky. Does that mean that early in your time at 
Stanford you got involved in administrative issues? 

Schawlow: No, not very early, but these things were decided by the 

department and the department had to be unanimous on them. I 
didn't spend a lot of time on it, but I took positions on these 
issues. I just went to talk with him [Panofsky] once, didn't 
try again. In 1966, Leonard Schiff, after eighteen years, 
decided that he'd had all he could take as chairman-- I think 
the struggle to keep SLAC in its place had worn him down. 

SLAC did do some things. They announced that Drell was 
going to give a course in general relativity, I think, which he 
was very well qualified to do, but still this was sort of an 
end run around the physics department. 

And Administration; Department Chair. 1966-1970 ftf 

Riess: You were saying that in 1966 Leonard Schiff decided he'd had 
enough of being chairman. 


Schawlow: And I was foolish enough to accept the chairmanship. I 

remember when I started I realized that practically every piece 
of paper that came to me was routine, but I didn't know the 

I was chairman for four years, and I was very glad to get 
out of that. It was a lot of work. You had to know what 
people to consult on various issues and make sure you did spend 
time talking with them. The experimentalists were much 
concerned about the workshop. The theorists didn't care at 
all, but they cared a lot about the library. So you had to 
spend time talking with people. 

I don't think I was a very good chairman. I wasn't very 
aggressive to try and expand, which we probably could have 
done. But still, I did keep the lid on, and things were 
reasonably peaceful when I was chairman. 

Riess: Did the department have a strong tradition of journal groups 
and meetings and symposia? Does the chairman keep alive? Is 
that part of the job? 

Schawlow: Well, you have to appoint committees. We would have a 

colloquium committee, for instance, that would be responsible 
for getting speakers for the colloquia. They'd have a lot of 
other committees to do things. The chairman had to appoint the 
committees and had to recommend raises for people, which was 
difficult because there never was as much money as you'd like 
to have. There I consulted with Leonard Schiff and we sort of 
went over them together. 

Riess: And sabbaticals, you had to decide on that as well? 

Schawlow: Yes, but there usually wasn't too much trouble with that. 

People usually had organizations that they could turn to for 
funding such as NSF or other laboratories, and they had 
postdoc's and so on to help cover when they were away. I don't 
remember sabbaticals being a problem. 

Riess: Were there any interesting people brought onto the faculty when 
you were chairman? 

Schawlow: I don't think so. As I say, I don't think I was very good at 
going out aggressively and getting people. But we had no 
encouragement to expand, and we had a good, strong faculty so I 
sort of let it ride as it was. We did make a few offers. We 
were trying to get an outstanding theorist, but the presence, 
proximity of SLAC was a detriment. 

Riess: Because that's where they wanted to go. 












Either they wanted to go there or they were afraid that they 
would be drawn into the discussions at SLAG. It just was 
difficult and so we didn't get one man. 

Interesting, I really had no idea that SLAC was such a black 

Yes, it was difficult. Of course, if they went to SLAC they 
wouldn't have to do any teaching, and they had a big group-- 
particle physicists seem to want to hunt in packs. 

Felix Bloch especially objected to that. He felt that each 
theorist should stand on his own. Well, it's a field where the 
problems are fairly narrowly defined. Somebody gets an idea 
and then everybody rushes to elaborate on that idea. Anyway, 
it was not the kind of theory that Bloch was used to, and he 
didn't like that. Nor, I think, did Schiff. 

What about women and minorities? 
in those years? 

Were those important matters 

No. No, they weren't. That's more recently we've tried to do 
something about it. We did start making some efforts to get 
minority graduate students, and we got some. But we didn't 
have any women faculty at that time. 

Do you mean on staff? 

On staff, no, we didn't have any women on the staff. It wasn't 
pushed pretty much. I think it's been more important later. 
But the trouble is, frankly, if you have an appointment, and 
you're not going to have another appointment in that field for 
some years, you try and get the very best person you can, and 
that isn't very often a woman or minority personbecause there 
just are few of them, and chances are very great that if you 
really have to get a top person, it won't be a woman or 

There's also a 

You were chairman of the physics department, 
chairman of the applied physics department? 

Yes there was. 

Did these larger questions get chewed over between the two? 

No, no, we didn't really have very much contact, and that's 
probably my fault. Later on, people did try and get more 
coordination between the two departments and they had regular 
meetings of the chairmen I guess it was. But not at that time. 
I just wanted to get on with doing some physics. 




Yes. And in fact, you didn't need to say yes. 

Why did you say 

Well, I looked around, and either you do it or somebody else 
will do it to you. [laughs] I just couldn't see anybody that 
was any better. After I got out I sort of pushed for my 
successor who, well, was only moderately successful. You have 
a limited number people thereit was a small department. 
However, they have managed and have had a succession. 

I did one year as an acting head when my successor wanted 
to take his sabbatical, and that was sort of a nightmare, 
because one day some students came to me and presented a 
petition that we recognize the graduate student research 
assistants as a union [bargaining unit]. Research assistants, 
mind you. This struck me as absolutely ridiculous because 
these were just people who were being given some money to help 
support them while they did their own thesis. But this thing 
had obviously been drawn up by a lawyer, so I could do nothing 
but hand it over to the university. I couldn't talk to them at 
all, tell them that I thought they were stupid. I couldn't say 

And it was probably for the entire university? 

No, just the physics graduate research assistants. Well, 
ridiculous. Eventually it got to the labor relations board and 
they decided that it wasn't a sensible bargaining unit and that 
ended it. But I had to deal with that. 

Riess: Also you had some dealings with the free speech movement? 

Schawlow: Oh God, yes. I was chairman of the university's research 

committee at the time of the Cambodian invasion. The committee 
had already decided that they wouldn't allow any secret 
research that had been banned. There had been some secret 
military research, in engineering particularly. They had 
allowed that research could have some classification if it were 
such things as needing to know the launch date of a satellite, 
something like that, which was considered secret information. 
But even that we had about decided to stop. 

I had to go around with Bill Miller, who was then 1 think 
vice provost for research, or something like that, and go to 
departments like the music department and German department, 
and explain to them what research was, let alone classified 
research. The radicals wanted to stop all government-sponsored 
research, all defense-sponsored research. 





So why were you going to the humanities departments? 
explain all this? 







They didn't know anything about it, and it eventually would 
come to a vote of the faculty senate. The issue was ending all 
government-sponsored research, which would have been utterly 

Were university-wide meetings called? 

Yes, there was a meeting of the senate I particularly remember. 
They'd had this research committee, and a subcommittee on 
classified research, which was supposed to make sure that the 
classification was only incidental and not really secret stuff. 
The subcommittee had clearances, so they could see. One of the 
members of that subcommittee got up at this meeting and 
denounced the research committee for allowing classified 
research. Oh! It was disgusting. I had to get up and point 
out that we'd already stopped the classified research and 
that'd only been incidental. 

Was Stanford brought to a halt in the way Berkeley was? 

Not as much. I think there were a few days. Leonard Schiff 
was very active in going to talk with students and student 
groups about things. There were some sit-ins. 

Did you have anyone like Charles Schwartz? 

No, nobody quite as bad as that. Charlie Townes was president 
of the American Physical Society and had to contend with 
Schwartz, who tried to get things done theresilly things. 

However, we had Bruce Franklin who was an English professor 
who actually incited the students, you know, saying, well, he 
wouldn't turn his back on people who use violence, something to 
that effectnot exactly telling them to do it, but sort of 
encouraging them. Fortunately, they had long hearings 
afterwards and they did fire him, which was a good thing. But 
he was a pretty troublesome person. 

Was he a professor? 

He had tenure and everything, but they got rid of him. 

Okay, so other issues while you were chairman? 

Well--. You had to get unanimity for everything. There were 
people who didn't like a couple of associate professors and 
didn't want to promote them, but I managed to get these 
reconciled. Frankly, I felt it was foolish to make a big issue 


of promoting from associate to full professor. The guy has 
tenure, he's going to be there anyway. So why do that? You 
can still make his salary less than the person who's brilliant. 
But I did smooth those over. 

Riess: Is there a system of assessing teaching ability? 

Schawlow: Yes, there is. We have to worry about that some, but as long 
as it comes out adequately--. We have faculty members sit in 
on other faculty members' lectures. And they have to put out 
questionnaires at the end of every quarter for students to give 
an assessment of the thing. 

Riess: And they do that conscientiously, or is that just honored in 
the breach, or whatever? 

Schawlow: Well, we have had cases later on, not in my time. We had an 

assistant professor who was a brilliant theorist but not a good 
teacher. We had a very hard time getting enough good things 
said about his teaching in order to get him approved for 
promotion to associate professor. We did, but he decided to 
leave anyway. He took a job at a national laboratory. 

Riess: As you go up through the ranks do you teach less? 

Schawlow: No, it's about the same all the time. Leonard Schiff had kept 
the number of courses down so that we had reasonable teaching 
loads. It didn't change. 

Riess: Your research associates and teaching assistants would be your 
graduate students? 

Schawlow: Yes. The teaching assistants would be the graduate students, 

not necessarily the same ones who were doing research with you, 
but there would be a bunch of them assigned to each course. 
They would have discussion sections and they would do all the 
grading. I never had to do any grading. 

Making up exams was always something I hated, though. I 
did my best, but I found that when you have a big class, no 
matter how carefully you word something, have it checked by 
several people, there is always somebody who finds a different 
way of misinterpreting it. 

Riess: Isn't there a tradition of finding brilliant alternative ways 
of looking at things? 

Schawlow: Well, of course you're trying to do that, but when you have an 
introductory physics class, usually they just misunderstand 


what it is you are trying to say--even though you tried to word 
it as clearly as you possibly can. 

And worse than that, teaching these introductory 
classes- -which I enjoyed in some ways because they had a lot of 
demonstration experiments to do--you can't ask for anything 
very difficult because it isn't a very advanced course. So you 
have to keep repeating similar things, but you know that the 
fraternities at least have files of the old exam papers. So 
you have to try and keep finding something different. After a 
couple of years it gets really pretty hard. I did keep 
switching around different courses of teaching every few years, 
but still making up exams was something I was very glad to get 
rid of when I retired. 

Riess: Do you think that there's been any anti-Semitism in the 

Schawlow: No, no. In fact, somebody who had been there as assistant 

professor said, "That's a nice little Jewish department they 
have there." And in fact they hadwell, Bloch, Hofstadter, 
and Chodorow, for instance. But they weren't all Jewish. But 
no, anti-Semitism, if there 'd ever been any, there wasn't any 
when I was there . 

There had beenI noticed at the University of Toronto when 
I was a student, as far as I could see there were no Jewish 
professors at the university before the war. There are now. 
They just didn't--. It's not the virulent anti-Semitism that 
you have in Germany, but well, they just didn't think those 
were nice people to have around. Of course, a lot of the 
Jewish people there were immigrants, fairly recent immigrants 
from eastern Europe, and they were different, but they have 
plenty of Jewish people there now. 

At Stanford, by the time I arrived, it was not a problem. 
I guess Bloch was probably the first one and he came in 1933, 
so he'd been around a long time. 

Riess: Yes, that's right. And the kind of scapegoating usually just 

has in part to due with the fact that there's a lot of economic 
pressure and so you look around and wonder who's getting it. 


The Family 

Settling into Palo Alto 

Riess: In these last minutes, why don't you tell about how you settled 
your family here. 

Schawlow: I came out in April for interviews, and in May I decided. Then 
I came out in June, and I had two days to find a house. We 
found this house. It was an Eichler house. 

Riess: Aurelia came out with you? 

Schawlow: No. She couldn't. We had the three children then. But she 
let me decide. And I figured this was a standard California 
house. We could always sell it and move to something else. 
Well, we never did, we got in there and Just sort of adapted 
ourselves to it. 

Riess: It was in a new tract then? 

Schawlow: Actually, it was three years old. It was the oldest house in 
that section of Stanford. They'd opened it up in 1958, and 
Eichler builds faster than other builders, so it was the first 
one finished. It had been owned by a librarian who had moved 
to become head librarian at University of Nevada. Then it had 
been rented by somebody, and it just came on the market the day 
I was there because the renters had a daughter graduating from 
high school and they wanted to wait until after she'd had her 
graduation to show it. 

I checked with Aurelia, it was all right, and I decided to 
buy it. We paid just $27,000 which is what we eventually got 
for our house in New Jersey. I sold it recently for $457,000, 
so inflation has really taken place there. 

Riess: Yes. Eichler houses were quite stunning, modern. 

Schawlow: They're more open than I would have liked. I'd like to have 
more closed-off sections. But it was all right. We got used 
to it. It had some advantages. It had this radiant heat in 
the floor, which is very clean and the floor was always warm in 
the winter, so you could go around with bare feet. It was 
built no worse than it had to be, and no better either, I 
think. But it was well designed and well situated. Big 
windows on the north and east sides, very small windows on the 


south and west, which are the hot places. It was comfortable. 
We thought of moving once or twice, but we never did. 

Before we came we had hired an au pair girl from Sweden. 
She went with Aurelia to Aurelia's parents' farm in Greenville 
while the move was going on, because the house would be all 
packed up, and I came out here to meet the movers. Ingrid [the 
au pair] had a boyfriend that she'd met somewhere who lived 
near there. I think the day she came here she called this boy, 
and his father had died just that day, but he came to see her 
anyway. They were quite friendly for a while, though 
eventually she married a friend of his here staying in the 
United States. Not the one that she'd known before, but a 
friend of his. 

The point is, we had this au pair girl, and she would work, 
I don't know, five days a week, eight hours, something like 
that. But I found I was spending thirty-five hours a week 
taking care of Artie, and on the weekends and so on. 

I had been approached by about eight different universities 
that year, because it was the first year after lasers operated, 
but the main reason we decided to come here was because of 
Peninsula Children's Center. The Hofstadters had an autistic 
daughter, and Mrs. Hofstadter had helped set up the Peninsula 
Children's Center, which was at that time a school for 
handicapped children that met in an old house way out in a back 
part of Stanford. Here was a place for Artie to go. So 
proximity was probably the deciding reason we came here. 

Autism and Artie ff 

Riess: You've said about Artie's autism that they didn't know that's 
what it was. 

Schawlow: They didn't know what it was and they didn't know what to do 
about it, either. The name had only been invented, I think, 
about ten years before he was born, and nobody knew much about 
it. By the time we came out to California he had the label of 
autism, but it didn't help much. There was no real government 
funding for people with autism. 

There was one juvenile court judge here who was willing to 
make autistic people ward of the court in order to get them 


whatever services they needed. We didn't have to rely on that, 
but there was this day program that was set up in a house on 
the Stanford property [referring to Peninsula Children's 
Center] . 

The first year Artie was there it was a good program, but 
after that the woman who was running it left and Artie didn't 
seem to take to it. He would go but he'd just sit off by 
himself and not participate in anything much. 

Riess: How did your respective families deal with this when you were 
back on the east coast? Was there some sympathy? 

Schawlow: Oh, yes, there was certainly sympathy. My mother was always 
good with children, and she liked Artie. She would visit 
occasionally and they would get along well. 

Aurelia's parents were older; Aurelia was almost the 
youngest in a large family. They did visit. Her mother, I 
remember, visited us. Oh yes, we took Artie down there several 
times and people were sympathetic. But he was little, and at 
first you couldn't really tell whether he was slow starting to 
talk or what it was, because he wasn't aggressive or anything 
like that. He just was sort of a loner. 

We really didn't know how bad it was until he got to be 
about four or so. Then the only thing we could find in New 
Jersey was a pediatric neurologist. She thought it was petit- 
mal epilepsy, had some sort of an EEC taken, but I gather that 
EEC's don't mean anything much at that age. And she prescribed 
some kind of a drug for epilepsy. That made him incontinent, 
and so he had trouble. He was going to a nursery school, or a 
day care place. That was a difficulty. I think he had to 

Riess: But having a name for his illness must have been some help. 

Schawlow: Yes, it was I think. And later on it became a greater help 
because there became funding for autism- -but that was much 

[sighs] Oh! At Stanford we consulted a psychiatrist, and 
he didn't want to look at Artie, he just wanted us to talk 
about what it might be that we were doing to unconsciously hurt 
this poor child. After a few months I gave that up, though 
Aurelia continued to go to him. But I think he was harmful. 

We also went to a neurologist at Stanfordthey tried to do 
an EEC, and Artie was upset, so they gave him a strong sedative 
which I'm sure made the results pretty meaningless. Then the 


neurologist thought amphetamines might have a paradoxical 
effectthey sometimes doand calm him down. Instead, they 
just made him more excitable and made him more locked into 
doing things over and over, like jiggling shoelaces or sifting 

He would do that for hours and he wouldn't eat anything 
much. I forget- -he would drink orange juice, but I don't know 
what else it was, there was very little that he would eat, but 
somehow that turned out not to do any serious harm. But this 
amphetamine was keeping him awake until one o'clock in the 
morning, so I had to be up with him until then. 

He liked to go for rides in the car, and go swimming, which 
we'd been able to do in New Jersey, and also at Stanford when 
they opened a pool. Then he got to running away, and we built 
a big fence around the back yard and put in hooks on the doors. 
But you'd forget sometimes and then get a call early in the 
morning and he was in some neighbor's swimming pool. He wasn't 
in any danger, but--. 

So, we were kind of desperate. Molly Hofstadter had gone 
to a place, Clearwater Ranch in Mendocino County, where they 
had people who were supposed to have mental handicaps. (Well, 
autism is kind of physical and mental.) We sent him there for 
the summer when he was seven, and the next year we sent him 
there to stay. That was a pretty good place for him. We would 
visit him practically every week, and have him down 
occasionally--! would go up and bring him down for the weekend. 

Riess: Was there any kind of communication with him? From him? 
Schawlow: Not really, no. 

Riess: You must cut me off when it just becomes too intrusive, but for 
me it's learning also. 

Schawlow: Well, I may start crying, but I'll keep going. 

[close to tears] Well was there any communication? No--. 

Riess: You were speaking to him, I'm sure, all the time and the 
question is--. 

Schawlow: Yes, but we were not doing the things we should have. We 

didn't tell him he was going to this place; we just took him 
there and left him. We didn't know whether he could understand 
it or not, we couldn't tell. He Just didn't show much sign--. 





He'd been up at this ranch for a couple of years and we'd 
go and see him often, take him out on outings in the woods, 
have a picnic or something like that. Or sometimes we'd bring 
him home for a weekend. 

But then there was a very nice lady, Grace Turner, who was 
running what they called Townhouse. It was a house in the 
little town of Cloverdale, right on the main street. She saw 
Artie, and he reminded her of a boy with whom she'd had some 
success, and actually had gotten him to begin speaking. So she 
asked for Artie. Those were good years. He was there for 
several years. And that's where he learned to read, he tells 
us. He was ten years old. She taught him to read. But he 
didn't show us at all. We didn't realize it. 

Then when he got to adolescence- -they had young girls there 
and they were afraid of him. I don't think he had been hitting 
anybody then, but he began to have some tantrums and so they 
felt they couldn't keep him any longer. 

You mean at Grace Turner's house? 

Well, Grace had left, I forget just why. The last year or so 
there [at Townhouse] they had been taking him down to a day- 
school program, but he apparently hadn't been participating 

Through all of this, the understanding of autism must have been 
changing . 

Schawlow: Yes, slowly. 

Schawlow: Bernard Rimland--he' s a psychologist who was working for the 

Navy in San Diego but he spent a year at the Stanford Institute 
for Advanced Study in the Behavioral Sciences he wrote this 
book in which he came out flatly saying autism was a physical 
problem and not just the mother was not warm enough. 1 And the 
people began to change their attitude toward it, but they still 
didn't really know anything. People began to use behavior 
modification, which is helpful in some cases, although it can 
get too rigid if that's the only thing you do. You know, where 
you reward good behavior and not bad behavior. 

'Bernard Rimland, Infantile Autism, The Syndrome and Its Implications 
for a Neural Theory of Behavior, Appleton-Century-Crofts, 1964. 


But that didn't reach us, really, any of that. We tried to 
find another place for him. Oh, several places turned him down 
because they didn't know how to deal with autistic people. 
There was one place that had retarded children. He just didn't 
fit their type. Then we got into a farm near Petaluma. He was 
there for some months, but again he was being very withdrawn 
and not cooperating with the program, tearing up bedsheets, 
things like that. So they kicked him out. 

At that point, there wasn't any place to go but Agnews 
State Hospital, or as it is now known, Agnews Developmental 
Center. We went down there and they told us about all these 
vocational programs they had. We thought, well, it might be 
all right, but what they did actually was they just doped him 
like a zombie, and they never had any vocational programs for 

[sighs] He was occasionally violent. He broke somebody's 
finger, I think, slamming a door. I think they sort of were 
very wary of him and really didn't do much for him. And it was 
a terrible place, just terrible. Very noisy, with a lot of 
other people and the bad things they did, like smearing feces 
around. We tried taking him out. We tried taking him at home 
for some weeks and getting somebody to take him to a day 
program. Well, he hit that girl and she wouldn't do it 
anymore. So back he went. We kept looking. We found a place 
in Concord where they took him for a few months. And we were 
paying for an extra person, but they still felt they couldn't 
manage him. So that didn't last and he had to go back to 
Agnews . 

Finally- -Agnews was trying to get rid of him. We had 
gotten a court order making us conservators with the right to 
control his medication and got them to stop giving him drugs. 
They were so angry at that they tried to kick him out, and they 
tried to persuade us to take him to Napa State Hospital, which 
had something that was alleged to be a program for autism. 
Well, 1 went up there with Aurelia, and then Aurelia and Helen 
went up there and spent most of a day, and decided that was no 

We asked the woman who was the head of the [National] 
Autistic Society chapter in Sacramento, Marie White, if she 
knew any parents of people at Napa. She said, "Oh, don't go 
there. It's no good. But maybe he can get into this place 
where my son is." This place was in Paradise. (And she had 
had lots of fights with the authorities and forced them to find 
a place for him.) This man in Paradise [Chris St. Germain] had 
this school called Paradise School for Boys, which had 
teenagers who were going out to day programs, to school, and so 


on. He had admitted her son Doug White as a special case. 
They got an exception. 

Then he looked at how much they were paying for adult 
autistic people and he thought he'd make more money. So after 
some months he managed to get his license changed so he could 
take adults and switch over to that. Well, he wasn't very 
smart. He didn't realize that the adults required a lot more 
staffing because they weren't in school all day. Artie had 
been there just a few months and-- 

Riess: How old was Artie at that point? 
Schawlow: I think he was twenty- seven. 

After a few months, Mr. St. Germain came to us and said he 
was going to have to close the place. He had broken up with 
his rich wife, was losing money, and couldn't afford to keep 
going. Well, we took a mortgage on our house and lent him 
$100,000. It was about 1983, so--it was after we got the Nobel 
Prize. We lent him the money and he kept going for a while. 

We tried to get some sort of check on his financeshe had 
an accountant looking over his figures, but she wasn't doing 
her job, she would just take anything he gave her. He was 
going through this [money] so that by 1985 he was running out 
of money again. Apparently he had to admit that he'd been 
dipping into his clients' money. I thought he was going to 
lose his license. 

But Marie White and I had set up a foundation, a non-profit 
organization which we called California Vocations [Inc.], 
because we wanted to provide some vocational training for the 
people there. But we found we couldn't put money into this so- 
called for-profit organization, we couldn't find a way. Well, 
when we saw this trouble coming and he was going bankrupt 
again, we had the charter changed so we could operate a group 
home. By the early fall of 1985 we were told that if he [St. 
Germain] stayed the income tax people would close it down 
because he owed $58,000 in back payroll taxes. But if somebody 
else took over, they would follow him for the money and let us 
start fresh. So with essentially no warning at all, we took 
over and he disappeared. 

We took over, not knowing what we were getting into. We 
had hired a lady bookkeeper, retired from one of the big 
aerospace companies. She had tried to keep him straight but 
couldn't. Then we got some friends from our church to help us 
on the board and one of them straightened out the books. She 
[the bookkeeper] had been treating the books like she might her 


household expenses, not really keeping things well-budgeted and 
careful. But we did get the books straightened out and hired a 
new director who's still there, Phil Bonnet. 

Riess: He had studied autism? 

Schawlow: Yes, and he'd worked in several group homes before. He had a 
degree in psychology and had worked in several group homes. I 
think the regional center had not trusted Chris St. Germain, so 
they didn't keep his place full. That was one reason he was 
losing money. They took somewhat better to the new management 
and let us fill up. He [Bonnet] has managed to keep the 
budget balanced, although it's been very tight and we don't do 
all the things I'd like to see us do for our clients. I've put 
in a lot of money, given them a lot for very special purposes. 

When Aurelia died, I had some stock that had gone up in 
value and I gave them something like $125,000 to build a 
recreation and training building, now known as the Aurelia 
House. That was a success, they got a good builder and he did 
a good job on that. Artie doesn't use it much anymore because 
we rented an apartment in Paradise which we could use when we 
went up there, and Artie comes down there nearly every weekday 
when he has one-on-one. He blows up occasionally, and at one 
point they got the regional center to give him one-on-one 
staffing for five days a week. 

Riess: The regional center administers the disability money? 

Schawlow: Yes, that's right. There are nominally private organizations 
that administer the state's money. They are, of course, very 
much the creatures of the state. They have to do what they're 
told. We are still supported by the San Andreas Regional 
Center which is down in this area, and not by the Far Northern 
Regional Center. The Far Northern has been rather tight in 
providing extra services, and so I felt it was better for us to 
stay where we were. 

Riess: So he gets one-on-one-- 
Schawlow: --five days a week. 

Well, they say he's doing very well. He has epileptic 
seizures occasionally. They've been increasing in frequency, 
which worries me a good bit, and I've been trying to find out 
what's the matter. At one point where he had some bad 
outbursts they got the psychiatrist to prescribe Haldol, a so- 
called antipsychotic drug which has very bad long-term 
consequences, and also lowers the threshold for seizures. I've 
been pushing on them to cut down the dose and they have cut it 


Riess : 

some. I haven't gotten statistics lately of how frequent the 

seizures are. But they used to be one a year, 
been about one a month. 

and now it ' s 

So he does have a standard panoply of medications. 

Tegritol for the seizures. Tegritol and Haldol are really all 
he is taking. We've really made it clear that we did not want 
him to be heavily drugged. And he seems all right. He doesn't 
seem dopey like he did in the hospital. He really looked like 
a zombie there. 1 

Now, in addition to that, we have hired teachers to work 
with him one-on-one. There was a nice young woman who worked 
with him for maybe seven years or so, but then she got cancer 
and diedno, it was longer than that, I guess, that she was 
with him. It was only last year we hired new teachers. We 
didn't know which one to hire. Artie sat in on the interviews, 
and he didn't agree with Phil Bonnet, so we hired them both. 
The one Artie preferred was the better one, I think. And I 
hope she's still continuing. She took the summer off. I'm not 
sure that she's come back. The other one did quit after a 

What are they working with? 
facilitated communication? 

Are they working with the 

Schawlow: Yes, they've both learned to use the facilitated communication. 

The one he had before, Lindaoh God, I'm so bad with 
names he wanted to write with her. Just after we found out he 
could communicate, we found he also could write or print. 
Again, he wanted a hand on his. The way he did it was take the 
top end of the pen while the bottom end was in his mother's 
hand and manipulate it. With Linda he wanted to write and he'd 
write with big scrawling letters, about one word on a page. 
Apparently some other autistic people write that way too. I 
think they have difficulty starting and also stopping a motion. 
Although we've heard that you can use a squiggle pen which puts 
a vibration on the hand. Some autistic people can write 
smaller when they have that. We've tried it half-heartedly 
with Artie. I have to see whether it's being used now or not. 

'July 1, 1997. We have a new psychiatrist and a new neurologist. Art 
is not taking Haldol, and the neurologist has added another drug to help 
prevent seizures. [A.S.] 


Linda didn't know very much mathematics. She took him 
through grade school arithmetic. He already knew how to add 
and subtract, but she showed him how to multiply things, how to 
carry, and that about used up what she knew in mathematics. So 
we hired a junior high math teacher to teach him more advanced 
stuff. At one point, Artie said, "I can do so-and-so's baby 
math, but I really want something more advanced." So we got a 
man who was a lecturer in statistics at Chico State. He worked 
with Artie, went through algebra and I think was even getting 
into calculus. It's hard, though, to do, because Artie can't 
write very much and you can only ask him questions which he'll 
give you a yes, no, or a number for an answer. 

Riess: He can say yes or no? 

Schawlow: He'll type iteither type it or point to a card that has words 
on it. 

Riess: What impedes speech? 

Schawlow: I don't know what it is, whether it's difficulty in initiating 
it, or something is inhibiting it. But he has occasionally 
said a few words very clearly. At the Autistic Society 
convention last summer I ran into a number of people, about ten 
or so, who knew at least one autistic person who just very, 
very occasionally said something. So all the speech mechanism 
is there, but they just can't produce it on demand, I think. 

Riess: It is the most important diagnostic symptom? 

Schawlow: Well, there's a wide range of autistic people. Some of them 

can talk. Some of them use echolalia, where they repeat what's 
been said and what somebody else said to them. Like if you 
say, "Do you want to eat?" they'll say, "Do you want to eat?" 
really meaning they do. But he never did that. 

Failure to communicate somehow or other is a difficulty, 
but there's a wide range. There's some people now who I think 
are among the forefront who think it's a neuromuscular problem. 
They Just can't control muscles that they want to do things. I 
think there's a lot of truth in that. 

Riess: What does learning algebra do for the whole personality? 

Schawlow: I think it's something he wanted, he asked for it. He's 

certainly much more relaxed than he used to be. In fact, Phil 
Bonnet was mentioning that. He's participating more when they 
have parties, he's not so withdrawn. Although I don't think he 
really makes friends with the other residents. But he is quite 
friendly with some of the staff. 

Riess: They're all adults there? 

Schawlow: Yes. I have a movie--well, there are a lot of movies with 

Artie in them, but there's one--a film company from Luxembourg 
was making a series of Nobel Prize winners. I told them about 
Artie and they sent a film crew up to film him at Paradise. 
They used it, I think, for some medical program in Germany and 
Germanic countries. I have a copy of that film and also one 
where Artie was working with Aurelia and me using facilitated 
communication. There's also a video about Cypress Center in 
which he appears occasionally. 

Riess: Cypress Center was the name? 

Schawlow: Oh, this Paradise School for Boys we had to take over on very 

short notice and had to change the name because Paradise School 
for Boys had a bad name. It was on Cypress Lane so we just 
decided to call it Cypress Center. Turns out, we hadn't 
realized that just up the road, hidden behind some trees, 
there's Cypress Acres which is a large convalescent home. They 
do get confused. Mail gets scrambled sometimes. Probably 
should have taken a different name, but Cypress Center was one 
that didn't describe exactly what we were doing. I didn't want 
to do that. 




You and Aurelia really got into the whole world of autism, 
went to meetings. 


Yes, we did and we learned stuff. [First] the Los Angeles 
chapter of the Autism Society put on several conferences that 
we went to. It was good to see other people struggling with 
the same problems. We met some people there and got involved 
with the Autism Society. We weren't in the beginning, but we 
started going to their meetings. Met a lot of people and 
picked up a few things here and there. 

When Chris St. Germaine changed to this adult program he 
hired Gary LaVigna, who was one of the foremost experts on 
behavior modification for autistic people. He hired him as a 
consultant, but they never did implement much of his program. 
He also hired a very incompetent guy to be their psychologist, 
and nothing happened. But LaVigna sort of pointed them on the 
right track for a completely non-aversive program of behavior 
modification, where they just reward good behavior and-- 

No punishment. 

no punishment. No consequences other than what are 
unavoidable: if you put your hand on a hot pot, you'll get 
burned. That isn't punishment, but--. 

Riess: Is much money going into research on autism? 

Schawlow: I think there's more money now going into the medical side of 
autism, and there's certainly no doubt that it is a physical 
defect, at least caused by that. But of course, they have the 
strange perception and difficulty communicating that can lead 
to some bizarre behavior. I think there's not enough going 
into the behavioral side of it. 

There's a big program at Stanford looking into genetics, 
trying to find out to what extent some cases of autism have a 
genetic base, where in the genome that is. But frankly, I'm 
not very interested in that because it isn't going to do any 
good for my boy. There are people doing studies of brain, both 
by magnetic resonance and also by autopsies of autistic people. 
They slice the brain into small slices. They're finding 
abnormalities and getting a general idea where they are, 
although the brain is very highly interconnected, and so if 
there's something wrong in one place, it may cause problems 

I guess I like to see anything going on in the medical 
world, but I sort of feel that isn't going to help my son, not 
going to happen soon enough. On the other hand, adopting a 
teaching and somewhat behavioral strategy seems to help. 

Riess: It gives him a life. 

Schawlow: Yes. He's also held various part-time jobs. 

Riess: How does he manage to do that? 

Schawlow: Well, there's always somebody with him. They call it supported 
employment where there is somebody there, his job coach, in 
case there's any problems and also to show him how to do 
things. They've been rather menial jobs. Some of them haven't 
lasted long, not through any fault of his. He even worked for 
a while as a dishwasher in a restaurant. He hated that 
apparently, but the restaurant went out of business just about 
the time he got really fed up with it. 

Now he's doing some recycling a few hours a week. They 
started a recycling program because the town of Paradise 
doesn't have one. They distributed boxes and they go out and 
collect the stuff in the boxes and bring it back there. Some 
other residents sort it out. Somebody who's in the garbage 
disposal business buys it from them. He likes that. He likes 
going out. He's enjoyed emptying garbage pails for a long 


Riess: [laughter] 

Schawlow: He used to do it too much. He'd throw out things. 
Riess: Is he very strong? 

Schawlow: Yes, he's quite strong. Yes, I couldn't stop him from doing 
something he wanted to do. Fortunately this young man who's 
working with him now is bigger and stronger than he is, and he 
can handle him if there's any problems. 

Riess: Is the young man who's working with him a professional? 

Schawlow: He was in the Army Medical Corps for a few years and has 

qualified as an emergency medical technician. He's studying 
slowly to become qualified as a nurse. He's not in the full 
nursing program yet, but he's been taking things like anatomy 
and he has most of the requirements. 

Riess: I realize how usually I turn aside when I see people with 

needs. You know, maybe they have a cup out or something like 
that. But you must have a whole different view of the world. 

Schawlow: Well, I tell you honestly, and I've told other people, I really 
am only interested in helping Artie. But I know that to help 
him I have to help others. I have to keep this place going, 
for one thing. I've had a lot to do with that and risked money 
to have a place for him, and of course that benefits others 
too. Because you can't just have him by himself. I've still 
pretty narrowly focused on what might help Artie. I go to 
these meetings. I pick and choose among the sessions. 

Riess: I was just thinking that it's almost like a religious thing, a 
kind of compassion. 

Schawlow: Yes, well, you do have more sympathy for others. But I 

couldn't see myself actually working with these other autistic 
people. Certainly I do feel sympathy for other people with 
autism. They vary widely. Some of them recover almost fully, 
some of them are a little strange. Looking back, I know one 
person I remember who may have had some mild autism. He was a 
rather withdrawn sort of person. He worked as an accountant. 
I met another young man who got a Ph.D. in mathematics from 
University of Michigan. He tried teaching, but he just 
couldn't do that because he didn't have enough empathy with the 
students. So they come in all levels. Some are much worse 
than Artie. But yes, I do feel sympathy. 

I've tried very hard. We've brought in all the best 
experts we could find to consult there. It's been very hard 


because they really didn't want any outside interference and 
they sort of run a minimum program. They don't hurt these 
residents, but they don't really do nearly as much for them as 
they could. Like each house cooks their own meals, but I think 
the staff does the cooking. They should be training the 
residents to do that because some of them will move onto semi- 
independent living. 

They have one girl who demanded to have a place of her own. 
This is now the state's policy, to try and help people live as 
independently as possible. So they did get a place for her. 
Somebody checks up on her from time to time, probably every 
day. I don't know just how it works. 

Helen and Edith 

Riess: Your daughters, Helen and Edith, did they manage to have a 

normal upbringing in the face of all the concerns with Artie? 

Schawlow: Well, yes and no. I think I neglected them. I was there, you 
know, but I didn't play games with them or do anything much 
with them. But there's nothing I could do about it, I just 
did the best I could. But it was a struggle. 

Riess: They've gone on to interesting careers. 

Schawlow: Yes. 

Riess: Were they very academic girls? 

Schawlow: Oh, they were both pretty smart. Helen had a lot of trouble 
with mathematics. She got interested in French. Her French 
teacher at Castilleja, this private high school she went to, 
got her interested in French and she was very good at that. 
She has a very good ear for sounds. She could imitateshe 
could say a word in several different ways, in different 
accents, imitating different people. 

I think the public school near us at Stanford was really 
pretty bad. They should have drilled her more on arithmetic 
tables earlier and she would have done better. Because I think 
she's really not that bad. Now, she does arithmetic in her 
head quite competently. She just got started wrong. 

At this school, they combined fifth and sixth grades in her 
last year there. So they were reading this silly book, Little 


Britches, that she had read the year before in fifth grade. 
Then she enrolled in junior high and they put her in with the 
bonehead English class and the advanced mathematics class. 
Well, I think they were going to read Little Britches again, 
but at this point Aurelia decided to enroll her in this quite 
good private school, Castilleja. That's in Palo Alto. And 
there she did quite well. 

Riess: Did Edie also go to Castilleja? 

Schawlow: She went there for several years. Then she decided that she 

wanted to be in a regular high school--maybe she wanted to meet 
boys or something like thatso she went to Gunn High School 
her last two years. But she went through junior high and the 
first couple of years of high school at Castilleja. 

Riess: And then where did they go on to school? 

Schawlow: They went to Stanford. Fortunately, when I came there was an 

arrangement where children of professors, if they were admitted 
to Stanford, could get free tuition, but they couldn't get any 
help if they went elsewhere. 

Then about two years after I came, they changed the rules 
so that you could have half of Stanford's tuition anywhere. 
But people objected. I didn't, but they objected. So we had a 
choice, and I chose to have full tuition at Stanford. I 
thought that if they couldn't get in the Stanford, the state 
universities are quite good here in California and that would 
be okay. But fortunately both did get into Stanford and did 
reasonably well there. 

Riess: And lived at home? 

Schawlow: No. They lived in the dormitory. But of course they would 

come home quite frequently. It's only a mile or so away. And 
they'd bring home washing. 


Schawlow: Helen thought she might be a high school French teacher, so she 
went to Berkeley to get an M.A. in French education. [She] got 
very good training there through a very good man, Gian, an 
outstanding teacher, and she learned a lot about teaching. 
Then they sent her to do practice teaching in downtown Oakland, 
and she came out one day and a big man stuck a knife in her 
ribs and said, "You lay off my girlfriend." She didn't even 
know who his girlfriend was, but that was the end of her high 
school teaching career. 


Anyway, she decided to finish her master's degree in French 
there and came back and get a Ph.D. at home. By that time, 
well, she and her mother got on each other's nerves, so we 
bought a little house for her and she shared it, rented rooms 
to a couple other girls, and lived there quite happily. That 
worked out pretty well. Sometimes, young people do get on 
their parent's nerves, and vice versa. 

Riess: Let's finish off the rest of Helen's story. 

Schawlow: She got a Ph.D. in French at Stanford and she feels she also 
had some very good teaching experience here as a teaching 
assistant. Professor Hester was her master teacher, and he and 
Gian had written a book, an introduction to French, a first 
year textbook. She did all the exercises, to check out the 
exercises for them. So she was very well-equipped to teach 

But jobs teaching French were very scarce and I think maybe 
she should have waited a little longershe started applying 
for jobs before her Ph.D. was actually granted. You know, a 
lot of people unfortunately give it [that practice] a bad 
reputation by saying that they are going to get their Ph.D. and 
they don't, but hers was quite certain. 

She had gone with us to France on my third sabbatical in 
1985. While she was there she spent a lot of time doing 
research in French libraries and had good material for a Ph.D. 
thesis on an obscure surrealist writer, Pierre Unik--U-N-I-K. 
He had not written an awful lot, but he had been associated 
with some of the more famous ones like [Andre] Breton. He also 
had worked on films withwhat was his name?-- [Luis] Bunuel, I 
think it is, the famous film producer, who had mentioned him 
very enthusiastically somewhere and had said, "Why doesn't 
somebody write something about him?" 

Pierre Unik was one, when they had the split between Aragon 
and Breton--! think Aragon was a militant communist and 
follower of the party line, and he [Unik] went with him and 
wrote mostly for party newspapers after that. He was captured 
by the Germans and imprisoned during the war. I think he was 
drafted into the French army. He wrote some poetry then which 
people think is pretty good. Toward the end of the war he 
escaped from a German prison camp, disappeared into the 
mountains, and was never seen again, probably died. 

Riess: Quite a tale. 
Schawlow: Yes. 

Riess: Did she publish it? 

Schawlow: Yes. She got a little book published on that. It was a nice 
piece of work, although she didn't feel she wanted to continue 
that research. Now she's gotten very interested in French in 
North America, and is thinking of doing a book on that if she 
can get some time off. But it's very difficult. This 
university has a foreign language department, and just has two 
people in the French section. 

Riess: Which university is this? 

Schawlow: University of Wisconsin at Stevens Pointit's a branch of the 
university. It's quite big, but it's mostly undergraduate. 
There's only two people, so it's very hard for anybody to take 
time off for a sabbatical. They don't have money to replace 

Riess: And she has a family? 

Schawlow: Yes. But she has some ideas of possibly getting half-time off, 
and perhaps that can be done. 

Riess: When she thinks about North America, is she thinking back to 
her Canadian roots? 

Schawlow: Yes, well, Quebec and Louisiana. We went to Louisiana last 

May. There was supposed to be a festival of French culture in 
New Orleans, but when we got therethe whole family went she 
decided that it wasn't worth bothering with, so we just kind of 
explored New Orleans and then we went to the Cajun country, 
Lafayette and New Liberia. 

Riess: You must have loved the music. 

Schawlow: Well, the music in New Orleans was good. Not great, but good. 

Riess: I was thinking of the Cajun music. 

Schawlow: No, I didn't hear any unfortunately. I don't really quite know 
why we went there, except to see the places. We didn't really 
get involved with the Cajuns, as such. 

She has quite a collection of movies and records of the 
various kinds of Louisiana music. There's Cajun, Creole, and 
Zydeco. She knows the differences between all these. She gave 
a lecture to the Wisconsin Association of French and Language 
Teachers earlier this month, and apparently it was very well- 
received. She had about a hundred people. She showed a little 
film clip recording. She's very good at teaching. She had 





handouts for them, outlining how they could use this in a 
classroom unit on Louisiana culture. She's very good at that. 

But it's a tough Job, and getting worse because the 
enrollment in French in high school is dropping and so they are 
getting fewer who come with any high school French who would 
become French majors. They've had a lot of majors, they're 
second in the state or something like that, but if they come in 
with no French at all, they really can't do a major. Well, 
Spanish seems to be taking over the world. It has a reputation 
of being easier. I mean, here it's useful. In Wisconsin, 
they'd be better to learn French because there are a lot of 
French Canadians just across the border, not only in Quebec but 
in Manitoba. 

Just one more remark: she wanted to show something about 
these Cajuns who are working people, farmers and so on, to get 
away from the image of French people, the perfume sniffers, 
[laughter] But in fact, the students are really more 
interested in France and French culture. 

Our other daughter, Edith, is very bright, but never really 
much of a scholar. I think she did very well. She majored in 
psychology. Then she decided she would get a master's degree 
in nursing from UCLA. She went there after she graduated from 
Stanford in 1981. She had to take off a few weeks early in 
December to go to Stockholm with us and she didn't go back. By 
that time, she was very deeply involved with her boyfriend, 
Bill Dwan, and they got married the next summer. 

What's her last name? 

Dwan, D-W-A-N. It sounds kind of Chinese but actually it's 
Irish. I think it's a variant of Dwayne--D-U-A-N-E or D-W-A-Y- 
N-E, but it's Dwan. When I was in Ireland later, I looked it 
up in the phone books. There are two phone books for all of 
Ireland, one for Dublin and one for all the rest of it. It's 
not a big country. There are a number of Dwans around the town 
called Thurl, it seems. Maybe there are twenty or so, not very 

We were on a sight-seeing trip, my wife and I, and in 
Kilkenny we saw a truck and I almost swallowed my teeth because 
the sign on it said "Dwan's Makes Better Dwinks." [laughter] 
There's a soft drink company named Dwan and that's their 
slogan. Unfortunately, I didn't get a camera out quick enough. 
But later, Frank Imbusch sent me a couple of things with that 
slogan on it. 

So instead of getting her nursing degree, she-- 

Schawlow: --got married and has had three children. 

Her husband was from a Catholic family. In fact, he'd gone 
to a Catholic high school, and they were married by a priest 
who had been his high school mathematics teacher. I expected 
some difficulties, religious difficulties, but it didn't turn 
out the way I expected at all. Edie had not been much 
interested in religion as a childyou could drag her to Sunday 
school, but she showed no serious interest. But they fell in 
with some Baptists and before you knew it, they were both being 
baptized in a Baptist church, a rather fundamentalist group. 

Riess: Where is this? 

Schawlow: Well, they lived in Menlo Park at that time. They had a house 
in the country, in Woodside I think it was, where some 
neighbors were Baptist. Then they lived in Los Altos for a 
while. Then they got really deeply interested in religion. 

Bill wanted to do something to help religion. He had 
gotten a dual major or he'd gotten a B.S./M.A., I think, in 
biology and mechanical engineering. He thought he wanted to do 
something in prosthetics, or something like that to help 
people. He came from a rather wealthy family. His great 
grandfather was one of the three founders of the 3M Company, so 
he has a good bit of money, so he can do what he wants. He did 
work for the Veterans Administration but I think he found that 
they were treating him just as a technician, rather than part 
of the research team, doing programming. Then he took a job 
with Lockheed doing programming for a while, image processing 
for space missions. 

But then they said they wanted to do something with 
religion, so he got this job with a company called Walk Through 
the Bible, whose office was near Charlotte, North Carolina. 
It's actually in South Carolina, in the former PTL complex, 
this outfit from Atlanta has rented a building there. They 
were preparing materials for teaching Christianity and the 
Bible, making movies and other educational materials. He was 
doing some computer work there and he liked that quite a bit. 
That's why they moved to Charlotte, North Carolina. Houses 
there are cheaper. You can get a huge house for what he sold 
his house here. 

But just recently this year, that company has closed that 
office, decided that they couldn't afford it anymore, and he's 
now taken a job as a science teacher in a private elementary 
school. He enjoys the work. He may decide to get a teaching 
credential later. As I say, he can afford it, he doesn't have 


to work if he doesn't want to. But he's a very conscientious 
guy and wants to do something worthwhile. 

Riess: And what is your daughter's role in all of that? 

Schawlow: Well, she has three children which keeps her busy. But she 
also has gotten very deep in it and she's teaching a Bible 
class in this church of a small denomination whose name I 
forget. It's an offshoot of the Lutheran. Anyway, she teaches 
this Bible class every week I think, and does a lot of work 
preparing for it. I'm sure she does a good job. 

They don't seem to have any desire to come back to 
California. Charlotte is a nice town. It's growing very fast. 
It has a lot of big new buildings. It has a lot of things; 
there's a fine science museum, a concert hall, good hospitals. 
It's a pleasant city. It reminds me of Toronto when I was a 
boy- -you know, a moderate size city, not a megalopolis like New 
York. So they seem happy there. I think Bill doesn't really 
know what he's going to do eventually. He's an engineer at 
heart, I think. He's very good at fixing things, and 
apparently a good programmer, too. 

Riess: We haven't mentioned Helen's husband. 

Schawlow: Oh, yes. His name is Tom Johnson. He comes from a Swedish 
American family. Of course, Jansen is a very common name. 
It's spelled J-0-H-N-S-O-N, but the Swedes would pronounce it 
"Jansen." They're very, very proud of their Swedish heritage. 

He got a Ph.D. in anthropology from University of Illinois, 
and he's on the faculty in anthropology at this university 
[University of Wisconsin at Stevens Point] . They met at 
Stevens Point and got married and they have these two 
daughters. He's a very intelligent man and has diverse 
interests. He's wonderful at getting along with people. 
Indians was his specialty, American Indians, and he 
participated in the Sun Dance with the Shoshone tribe. He 
really gets their confidence. But he tends not to publish very 
much; he's a perfectionist who can't finish things off. So 
he's not famous, but he's a good anthropologist. 

Riess: I wonder about fame, the theme of fame in your family, and how 
your daughters have loved or resisted that. 

Schawlow: Well, I can't say much about that. I mean don't know much. 

Things were the way they were. I think they enjoyed going to 
the Nobel ceremonies, but I don't know. I don't think either 
of them had any interest in going into physics or doing 


anything with physics. If I had had more time with them as 
children, I might have played with them more, with Meccano or 
something like that, gotten them interested in mechanical 
things. Edie probably would have had the talent to do that 
sort of thing if she wanted to, but she never did really. 

You know, after Artie was such a disappointment, I never 
felt ambitious at all for the girls to do anything particular. 
If they're just reasonably normal, that's good enough. I never 
pushed them at all. 

So, is that enough about that? 

Riess: That is enough, yes. Did you have any graduate students who 
were girls? 

Schawlow: I had a few, yes. One of them, Antoinette Taylor, she was 
really quite bright and good at measuring things. One day, 
though, I was getting a bit worried about her. I had suggested 
some things that she might build, to improve the apparatus, but 
she didn't get around to it. I said, "Look, if you go on like 
this and never build anything you're going to end up in the 
traditional woman's position of taking measurements for some 
man. So you really ought to build something." She took my 
advice and did build an electronic circuit that they needed for 
the experiment . 

Riess: And so that was a breakthrough for her. 

Schawlow: I think so, a little bit, yes. She had all the ability she 
needed. She got married then to a theoretical solid state 
physicist, and they're both at the Los Alamos Laboratory in New 
Mexico. I saw her briefly at a conference in Baltimore a year 
or so ago, but I turned away to get a cup of coffee and never 
saw her again. [chuckle] Too bad. It was one of these big 

Riess: But can you actually make someone into a physicist? From your 
accounts of your own childhood, you were a physicist from the 
minute you could lift a pencil. 

Schawlow: I don't really know. I presume that anybody who comes to be a 
graduate student in physics has some interest, at any rate, and 
you try and find out what their abilities are. Some of them 
are really not at all creative, and they're just not going to 
be real physicists. They may be good at doing exams as 
undergraduatesoh, they're so different, there's such a 
tremendous range of abilities. 


Riess: I was reflecting on your comment about doing more with your 
daughters. Do you think the early education is essential in 
setting the stage for the development of a future physicist? 

Schawlow: Well, it could help. 

Arthur Schawlow at Columbia in 1949. 

Arthur Schawlow with a laser consisting of a rod of ruby cooled by liquid 
nitrogen and excited by light from a flash lamp reflected by an elliptic 
cylinder reflector. Stanford, 1962. 

Arthur L. Schawlow, 1991. 



Secrecy, Motivation. Morality 
[Interview 6: November 7, 1996] 

Riess : 



I think I asked you much earlier in these interviews what it 
was that bothered you about Joan Bromberg's book, which seems 
like an authoritative report on the laser in America, but let 
me ask it again, now. 1 

There are two things about the Bromberg book that seem to me 
less than satisfactory: one is that she somehow has the fixed 
idea that the military were orchestrating everything in this 
field, and it wasn't true at all. They did supply some money, 
but they really didn't initiate anything. When I was at Bell 
Labs, of course, they didn't look to the military for money. 
We didn't take any outside funding. At that point we could do 
whatever we wanted to do--as long as it seemed relevant, in 
some way, to communications. 

And I think also she gave a little too much credence to 
Gordon Gould who really contributed almost nothing to the 
growth of lasers. He had a lot of stuff written in his notes 
from time to time, [from] which he managed to get patents. But 
everything that he revealed later had already been found by 
other people. Those are the things that bothered me. 

How did you work with her? She interviewed you? 

Yes, she did. I guess 
of my articles. There' 

I gave her what materials I had, copies 
s a rather better book by an Italian, M. 

J Joan Lisa Bromberg, The Laser In America, 1950-1970, MIT Press, 1991 


I will say that the parts of the Bromberg book that I 
didn't really know anything much about, like the semiconductor 
lasers, seemed better to me. [laughs] I guess it's always the 
case that when a reporter, or even an historian, writes about 
things that you really know, it's never quite right. 

But she really is wrong on the motivations, at least for 
the early work. We just had no thought of military interests 
at all, really. It was a classic problem, really, like the 
search for the origin of superconductivity. This going from 
longer to shorter waves, and trying to get still shorter, is 
something going on through the whole history of radio from the 
beginning of this century--and one with which I was certainly 
very familiar. I think Charlie was too. I never gave death 
rays a thought, and I really expected that the first laser 
might produce microwatts or something like that. Whereas I was 
really very surprised when Maiman's first laser produced a 
kilowatt in short pulses. 

The military did start putting money in there. They wanted 
me to get a clearance and serve on committees, but I knew that 
if I accepted a clearance, I'd have two problems. One is that 
I would know things that I couldn't share with my students, 
which I didn't want to do. The other thing was that it would 
take a lot of time. I'd probably have been on every laser 
committee in the country. So I just refused to get a clearance 
until much much later, when I did get one to serve on the 
National Research Council's Committee to study ways of 
preventing forgery of currency using color copiers. That, I 
thought, was a worthwhile project. I don't think we solved the 
problem, but we made some suggestions. 

Our report had to be secret, of course. Still, some of the 
things we discussed are already in place, like the threads in 
the paper, and also some fine print. At the moment there's 
fine print on the higher currency, the hundred dollar bills and 
so on; there's fine print around the picture which is too fine 
for the current generation of copiers to copy. But that won't 
last, and I know they're in a running battle with the color 
copiers. It's so easy for a person who has something he can't 
share, like a girlfriend he doesn't want his wife to know 
about, or a drug problem, to just put a twenty dollar bill on 
the office color copier. You can get away with some amazingly 
bad currency if you pass it under the right conditions. 
Anyway, that was around the late eighties. But up until then I 
wouldn't take a clearance at all. 

Riess: How did you work on that problem? Did you get together as 
group each time? 


Schawlow: Yes, yes, we had a few committee meetings. I didn't do any 
work outside of the committee meetings. Brian Thompson of 
Rochester was the chairman. I got off it after, I don't know, 
a couple of years when they did our first report. But I know 
that the committee did continue. 

Riess: So the new Hamilton hundred-dollar bill reflects all of this? 

Schawlow: Well, some of the things that we talked about, not everything. 
It probably has some things that we don't even know about. 
They try to have secret [features]. There are some very good 
counterfeiters, a gang in East Asia that has moved from country 
to country apparently makes very good copiesthey even know 
where to put magnetic ink and so on. 

Riess: Well, it's probably a field worth studying. 
Schawlow: Yes, there's money in it. [laughter) 

I really never got very deeply involved in military things 
although you heard a lotpeople would come and tell me things. 
In fact, many years later Elliot Weinberg, who was working for 
the Office of Naval Research and supervised some of our 
contracts, said, "You know, there never was anything going on 
that you didn't know about." I think that's so. I really have 
the opinion that military secrecy usually hides incompetence, 
at least when it's military research. 

They had a project to make a hundred joule ruby laser, 
which cost a lot of money and didn't lead anywhere. They were 
trying to get weapons right away and the state of the art just 
wasn't there yetmaybe it isn't even now. It was satisfying 
to me that one of the first applications was for medical uses, 
for surgery on the retina of the eye. But I have very 
ambivalent feelings about the military. I don't like the idea 
of wars and killing people, they don't make any sense, but I 
know they happen. And I remember, of course, very well World 
War II when we were really faced with some horrible evil that 
had to be fought, in Hitler. In that case I was willing to do 
my small part, but generally I think it's a waste of time, most 
military research. 

Riess: In 1969 you published a paper in Physics Today called "Is Your 
Research Moral?". 

Schawlow: Oh yes, I have to talk about that next week. I foolishly let 
myself be inveigled into giving a presentation at a seminar 
that some undergraduate has organized on scientific ethics. 
He's gotten all the Nobel Prize winners around Stanford to each 


take one session, and mine comes up next week. I'm really very 
reluctant to talk about that. 

Riess: What did you say in the paper? 

Schawlow: Have you ever seen it? 

Riess: No. 

Schawlow: I'll get you a copy of it. 

What I said essentially was that people try to blame 
scientists for the consequences of their research, and that's 
ridiculous because you can never know what other people will 
add to what you have done. You just can't really predict the 
consequences, both good and bad. You just have to have faith 
that the good consequences will somehow outweigh the bad ones. 
And that's quite different from development, say, when you're 
trying to build an atomic bomb . I think people knew what they 
were doing. On the other hand, discovering the properties of 
nuclei, the people who did that clearly couldn't accept any 
responsibility for what was done with it. 

Of course, we just mentioned the example of lasers, where 
people talked right away about death rays, it was a very old 
idea from comic strips and fiction, but that wasn't what the 
lasers were like at all. In fact, there have been many good 
consequences. When I was in Akron and had the pleurisy, Dr. 
Bird bought one of his respirators and gave it to me because he 
was grateful because lasers had been used to do an operation on 
his wife that would have been very difficult without them. 

I still think that in the case of lasers there 've been all 
sorts of different applications that surprised me. I couldn't 
hope to imagine them because I don't know the needs in a lot of 
these different fields. The progress of lasers in many 
directions has been quite spectacular. Science is cumulative: 
everything that one person does is there as a foundation for 
other people to build on. Having said that, it's about all I 
have to say. 

Riess: Do you think that the ethics debate, or discussion, will end up 
being very challenging? 

Schawlow: I don't know. Of course, they have people there who are in 
biology and medicine, and well, they have different problems. 

One of the things about physics is that the results have to 
be reproducible. If you faked a result, people would find out, 
and that's a quick way to ruin your reputation. In some other 


branches of physics, particularly high energy physics, it's 
extremely competitive because there are only a few machines and 
they're narrowly focused on a few problems. And there, some 
really dirty work goes on to try and beat out the other guys 
who are working in that field. 

That really doesn't happen in the things I do. As I have 
told you, I am really one of the least competitive people you 
ever saw. Unless there's a student that is committed to a 
particular project, I would just as soon move out of the way 
and do something different if somebody looks like they're 
competing with me. 

Uses of the Laser. Unusual and Medical 

Riess: A number of things come to mind from what you're saying. First 
of all, having seen the Science in Action video, there's a 
charming part where you come in with a potato that your wife 
has suggested could be more efficiently peeled by laser. Was 
that in the spirit of emphasizing that it's benign? 

Schawlow: Well, yes, I did a lot of stuff to show that lasers were really 
not the death rays. That's one reason I invented the laser 
eraser, which workedand I even got a patent on it, at the 
urging of our contract monitorbut it never got used. But 
here was something you could build. People were talking about 
these death rays that you couldn't build, and here was 
something you could build. If it had ever gone into mass 
production, it could have been practical to have one built into 
a typewriter. If you make a mistake, you bring it back to 
where it was typed, press the zap key, and off it would go. 

I didn't intend to patent it or try to make anything of it, 
but I just wanted it as an example of something you could do. 
I thought people might take up the idea, but they didn't. 
First of all, IBM brought in the sticky tape for erasing and 
then word processor computers really took over. 

Riess: Could that ever have been cheap enough? The zap of light? I'm 
figuring that zap of light's got to cost something each time. 

Schawlow: Yes it does, but for a secretary's time when he or she only has 
to take out a few letters, a few characters, it would be cost 
effective. I had a letter from a newspaper publisher who 
publishes the Army Times, wanting to know if you could use this 
for de-inking newsprint for reuse. I did a rough calculation 
and said I thought the cost of the electricity would be more 


than the cost of the paper, even if the lasers cost nothing and 
were a hundred percent efficient, which they weren't. So it 
wouldn't have done for that. 

I did have a chance to make something out of it: National 
Geographic was, of course, very careful with their books, but 
they put out one book and they had right in the frontispiece a 
picture--! think it was either Arizona or New Mexico, but they 
had put it in the wrong state and they wanted to know if I 
could erase a hundred thousand copies of this thing. Well, I 
wasn't set up to do that. I think it could have been done, but 
I hadn't engineered the thing. 

Riess: You mean it could have been done through the layers? 

Schawlow: No, you'd open the page and zap the thing that you wanted to 
get out. It wouldn't take very long, just open the page. 

I also got some interesting correspondence. There was a 
man up in Oregon who was in the lumber business, and he wanted 
to know if you could use lasers for cutting wood. I wrote back 
that yes, you could do it, but the lasers we had were too small 
and inefficient. He said he knew that, but he was trying to 
look ahead to see what could be done in the future. He was 
saying that in cutting trees sometimes they'll hit a hard part, 
or somebody may have put a nail in the tree, and that'll break 
the saw blade and maybe cause a dangerous accident. He thought 
the lasers would be better. He was right in a way, but the 
question of timing--! don't know, I think he died before he got 
a chance to do anything on that, a few years later. 

It certainly is good to look--. I felt the applications 
have to come mostly from the people who have the needs . And 
the eye doctors are a great example. I think I've probably 
said already that neither Charles Townes nor I had ever heard 
of a detached retina. But the doctors knew about them, and 
they knew that they could prevent detachment by putting in a 
flash of bright light. Originally, I think somebody in 
Switzerland started it with sunlight. And then they used xenon 
arc lamps. The laser was a brighter light that could be very 
sharply aimed. So they knew what to do with it right away, and 
within a couple years of the first lasers they were beginning 
to use ruby lasers for preventing retinal detachment. 

Riess: What does it do? How does it work? 

Schawlow: It puts a little scar tissue on that sort of welds the thing 

together. The retina, I understand, is not really attached to 
the back of the eye. It's just pressed against it by the 
fluid, and if it develops a tear then the fluid can seep in 


behind it and lift it off, and then you can't focus. In that 
case, the eye doctor has to go in and turn the eye in the 
socket and come in from the back. They can do it, but it's a 
fairly serious operation. But if they get it in time, they can 
prevent it by using a laser. 

The ruby laser wasn't ideal for that purpose. It had an 
advantage that it didn't hurt, but it wasn't absorbed strongly 
enough so that sometimes it would penetrate too deeply and 
rupture a blood vessel, in which case the surgeon would have to 
take over. But it still did save quite a few people's 
eyesight. I think Bob Hope was one who had a laser retinal 

Riess: So the lasers that end up in the hands of the surgeons get 
developed for that purpose by some middle person, not the 

Schawlow: Yes, yes, that's right. And I know one company, Optics 

Technology here in the Palo Alto area, did develop one of the 
earliest lasers for eye surgery. Dr. Narinder Kapany, a very 
inventive person, was the president of that company, and he 
worked with a couple of eye doctors here, Dr. Christian Zweng 
and Dr. Flocks. There were others, other places, but they were 
one of the first to do it. 

I'm not an engineer. I couldn't have done that, I don't 
think. Well, if I had dropped everything maybe I could have. 

Riess: But you can have a lot of roles in this business. You can be 
the physicist. You could possibly be the engineer. You also 
could be the entrepreneur, the developer. There are lots of 
directions that come out of all of this, and it's interesting 
that you stay clear of them. 

Schawlow: Yes, I didrather deliberately. I know there were a couple of 
students in the business school who wanted to form a company to 
make laser erasers, and I wouldn't have anything to do with it. 
They were going to raise money. 

But if I'd taken on that responsibility, it would 've been a 
full-time job and I wasn't really sure of success, that I could 
make it practical. Well, you just have to choose, all the 
time. It's hard. I mean, sometimes you make mistakes. I've 
certainly made mistakes. I made a bad mistake in not trying to 
build the first laser, which I did know how to do but I Just 
didn't push it, I had a lot of other interesting things to do. 


Riess: Do you know yourself well enough to know what really "powers" 
you, as it were? It's not money, I guess. Money being often 
the thing that powers people. 

Schawlow: Well, as they say, "Money is maybe not the best thing, but it's 
a long way ahead of whatever 's in second place." [laughter] 

I guess I have to realize my limitations. I know myself 
pretty well, but I never can tell when ideas will strike and 
they may be quite a different direction than what I've been 
doing. So I enjoy getting at new ideas and trying them out. 
I'm not sure that I could undertake a linear development job 
where you have to do one thing after another. 

[telephone interruption] 

Schawlow: That call was from the new home where Artie lives. They have 
some problems. They have one young man who's been there for 
ten years, but lately he's started wandering into somebody's 
house nearby and they got very upset. They tried various 
thingseven put one of those alarm things on his wrist, or 
ankle, I don't know. But they've been unable to keep him in 
there, so they're trying to find another solution, try and rent 
a house somewhere that he can live in by himself for a while. 

Riess: Why do they call you about it? 

Schawlow: Well, he called me about various things. I'm a member of the 
board of directors. I'm vice president, I guess, and was 
really one of the founders of this place. But he also called 
about Artie, wanting to know if I was coming up this weekend. 

Riess: Now, you were saying that you didn't feel that you were the 
type to be doing a kind of linear development thing. 

Schawlow: Yes. Well, I don't know. I've never really done it. Maybe I 
could do it. Didn't really want to. 

Riess: Do physicists do this? Do they drop out of basic research? 

Schawlow: Oh, yes, sure. Lots of them do because there aren't that many 
jobs in basic researchit' s a great privilege to be able to do 
basic researchso a lot of them go into industry, and lot of 
them do jobs like that. I have one student who was in various 
research labs, and he lately was in Livermore. Then he took a 
job with a company that makes semiconductor lasers. But they 
want him mostly to do sort of sales engineeringcontacting 
customers and that sort of thing. 


Funding and the Military 

Riess: Back to Bromberg: one of the things that was interesting to me 
was the it's just so obviousthe amount of money that started 
flowing in and becoming available. 

Schawlow: I think a lot of it was wasted. 

Riess: One example, though, is ARPA funding TRG. 

Schawlow: Yes. Well, TRG and Gould probably did have more insight that 
lasers could be powerful. In fact, they got the Air Force to 
support them before any lasers were made after our paper came 
out. Gould made a deal with them to give them his patent 
rights, to license them under his patents and give them rights 
after on anything else he did. But he kept delaying giving 
them his initial stuff so that he had more stuff that was his. 
They [TRG] tried to get the Air Force to classify all the work 
on lasersthis was before anybody had made a laser and we 
simply told them that if they did that, we would stop working 
on it. They didn't. 

Riess: What was the dialogue? Who got in touch with whom about that? 

Schawlow: I don't know the details, but I think it was initiated by TRG 
and the Air Force. Which one started it, I don't know. But 
then somebody, I don't remember who it was, somebody at Bell 
Labs got word that that's what they were trying to do. 
Certainly my reaction, and I think others at Bell Labs, said, 
"Well, if you're going to classify it, we're not going to work 
on it." Because we wanted to do publishable things. We were 
trying to build up our reputations in physics. 

Riess: But the ABM defense idea? 

Schawlow: Oh, that was later, I think. That probably was one of the 

goals, yes, but that was so far beyond anything, that nobody--. 
1 don't know what went on in the military circles Charlie 
would know better than I on that but I would hope that they 
had more modest goals than that. 

Riess: Well, that's the way Bromberg explains ARPA funding TRG, 

because they were looking for ABM defense "Though no laser has 
yet been demonstrated, lasers were even then being taken into 
account. . . Ml 

The Laser in America, p. 82. 


And that leads to another book, The Physicists. 1 It's a 
book about physicists in America. The period we're talking 
about is a period of big money where it's hard to imagine greed 
not being a real factor. 

Schawlow: It really was. A lot of people started going into physics 
because they thought they could make big money. A lot of 
physicists took jobs with companies or started their own 
companies. Oh, a lot of stuff went on. 

I had a friend who, a few years earlier, had gotten his 
Ph.D. at the University of Toronto. I guess he had a teaching 
job for a while, but then he went with a company that was 
started in Cambridge, Massachusetts. There was a Harvard 
associate professor who found that several of his students were 
getting more money for their initial jobs than he was making. 
So he decided he was going to make a fortune and he started 
this company, hired a lot of people, and then sold it after a 
year or so. And it did make a lot of money because he just had 
assembled a staff --and although they'd never made any profits. 

There was a lot of that. It really didn't touch me much. 
At Bell Labs we didn't have anything to do with government 
funding. Not in our department. Bell had a military division 
at the Whippany Laboratory, but it didn't touch the basic 

Riess: What about the meetings at exotic locations, jet-setting 
around, and good salaries at the universities, then, too. 

Schawlow: Well perhaps. Certainly, well, I don't know how much that 
affected--. Of course, there were a lot of people at the 
universities who took jobs where they were paid mostly or 
partly by government funds . 

There 'd been a battle at Stanford. The engineers were into 
that heavily and engineering at Stanford had grown very big and 
very good. Our electrical engineering was either the best in 
the country or maybe MIT some years would be rated better. 


Riess: That's why they could offer so much. 
Schawlow: Yes, and could hire so many. 

'Daniel J. Kevles, The Physicists, The History of a Scientific 
Community in Modern America, Harvard University Press, 1987. 


Riess: The glamour field was high energy physics, which accounted for 
only one out of every ten physicists, but had a third of the 
federal funds. 

Schawlow: Well it's a very expensive field, and still is. Of course, 
they turned out Ph.D.s there who couldn't get jobs in that 
field, and some of them became computer programmers because 
they had been heavily engaged in computer programming in that 
field. And some of them went into different fields, I guess. 
Some of the people who got their Ph.D.s in high energy physics 
went into lasers because it was growing and had money in it. 

I remember a meeting in 1963 at Brooklyn Polytech. The 
excitement there was really palpable because there were a lot 
of people there from companies who wanted to know how they 
could get into this laser field. As I say, I think it was 
overblown but it was there all right. 

Riess: And by the end of the sixties, well--. 

Schawlow: Money was getting scarcer. Even when I started in '61 there 

wasn't as much money as there had been a few years earlier when 
you really could fund anything. But we managed to find some 
money to do some researchthat was from NASA mostly, and we 
had small amounts from the Navy and the Army. By the end of 
the sixties NASA decided that they had to be more selective in 
what they were doing and they couldn't support us. Fortunately 
the National Science Foundation was growing and we were able to 
get in there and get about the same amount of money from them. 

Riess: It was not just NASA. The whole country at the end of the 

sixties was taking a strong dislike to science, whereas they 
loved it in the early Kennedy years . 

Schawlow: Yes, well, it isn't just a dislike to science. I think there's 
a disenchantment with higher education. Perhaps that came a 
little later, butthe trouble is that universities had 
expanded so much that they were turning out an awful lot of 
people. And there simply were more educated people than there 
were jobs for them. 

I think in the early seventies they made some manpower 
projections that the teaching at every level, from grade school 
to college, was saturated and there really weren't going to be 
any large influx of jobs in teaching for a long time. For 
centuries that was the chief place where university people 
went. So I think there began to grow a disenchantment with 
higher education, which was so expensive, getting more 
expensivefaster than the cost of living. 


I think we're feeling that now and going to feel it more. 
There was one big disappointment: people thought, looking at 
the demographics, that there were going to be a lot of people 
to be educated in the nineties because there was sort of a 
second baby boom, but it hasn't happened. They thought the 
universities would have a lot of replacements and openings, but 
instead they've been squeezed in budgets and they're cutting 
out programs. Prospects for university teaching are not very 
good unless you're exceptional. 

Riess: That's interesting. So [in the sixties] there was that and 
then there was the whole bad odor of the military industrial 

Schawlow: We had very good relations with the military. 

Riess: No, but I mean the swing against science, don't you think that 
had to do with the military ties? 

Schawlow: Well, one of the problems was that the military, the Navy 
particularly, had taken a very far-sighted view that they 
wanted to have good relations with the scientists in case some 
emergency came up and they needed to enlist them the way they'd 
done in World War II. 

They also wanted to sponsor far-out work that might 
eventually lead to something more dramatic. You know, the 
question: do you want to improve the sights on the rifle or 
build an atom bomb? They had that sort of attitude. Partly, 
yes, they wanted to have good relations with the scientists. 
They were very good to work for. They didn't try to interfere 
at all and they had people in their liaison jobs who understood 
what we were talking about. They didn't try to make us justify 

Now Senator Mansfield was worried about the growing 
influence of the military on universities, and he put through 
thisthe Mansfield Amendment, I think it was called, which 
required that every project they have at the university have a 
specific military purpose. And that was really pretty harmful. 
Well, it didn't hit us very directly because certainly anything 
having to do with reconnaissance or communication served a 
military function. Work with lasers, I think, fitted into that 
pretty nicely without having very specific weapons-related 
things. But it was typical of the timehe was doing that 
because he felt that universities were getting too cozy with 
the military. 

Riess: And that that basic research was not--. 


Schawlow: Yes, that they didn't always have clear military applications, 
which was, in my mind, a perfectly sensible way to do it . 
because you couldn't know what was going to come out of this 
basic research. 

But they did support what was then high energy physics. 
For instance, the high energy physics lab at Stanford which had 
a one billion volt accelerator, on which Bob Hofstadter did the 
work for which he got his Nobel Prize, that was mostly 
sponsored by the Navy. Of course, they had advanced 
accelerator techniques. It was the first big linear 
accelerator and it helped in the development of large high 
power klystrons, spurred the development. 

Riess: Nibbling at the edge of the ethics issue is what the goals are. 
It sounds like it comes with the territory, doesn't it? 

Schawlow: Yes. I guess so. Well, my attitude has been expressed in that 
movie. I think I said that you do science because you think it 
may benefit mankind in some way, but when you're actually doing 
it you have to put all that out of your mind and concentrate on 
the problem itself. If it is basic science you just really 
can't try to aim it at a particular problem. 

On the other hand, it's true that money is available for 
some things and not for others. And it was available to some 
extent for lasers because they had, I guess, military 
application- -and one that I never thought of, which actually is 
the real one, was the target designators, where the plane will 
send a laser beam at a target and the bomb will home in on 
that, either from the plane or from somewhere else. I 
certainly had no idea of that. 

Whereas there was not that much money for some other things 
like maybe cosmic rays--I can't think of examplesacoustics, 
for instance, things that were not considered very important. 
Certainly there was money for underwater sound sort of things, 
ultrasonics, but not, say, for musical acoustics. 

Riess: Did you come down on one side or another of the space 
exploration questions? Have you spoken out? 

Schawlow: No, I avoided them. In fact, I didn't even get in a public 

debate on Star Wars, either, although unfortunately when Reagan 
made his announcement I think Time got hold of something I'd 
said a few months before about the impracticality of those 
things. But I didn't say anything more than that. 

Riess: And were you a member of the Jason Group? 


Schawlow: No, they really were after me and I did go to a couple of their 
sessions. I think I went twice for a day when they were 
working on some problem. My work was strictly unclassified and 
I didn't get involved in anything secret. 

Riess: That was your reason, that it would 've compromised your ability 

Schawlow: work with my students. I guess when it comes right down to 

it, I don't like having to keep secrets. I like to tell people 
what I know. 

Riess: When you were on the phone with the administrator of the place 
where your son Artie lives [Cypress Center] it made me think 
how much you would like, probably, to have made lasers work for 
him in some way. Have you thought about that? 

Schawlow: No, not really. I've often thought it would be nice to have 

some kind of a laser operation on myself, but fortunately I've 
avoided that. [chuckle] No, I couldn't see that lasers were 
going to help. 

Riess: I mean for some of the technology for learning. 

Schawlow: Well, I did spend a good bit of time trying to use computers 

[for Artie] without very much success. But I just never could 
think of any way that I could use lasers for him, so I didn't 
give it much thought. 

Riess: You say you weren't thinking about retinal surgery and yet it's 
such a wonderful result. Does your imagination run to problem 
solving or do you stay at the basic level? 

Schawlow: I try to stay at the basic level. I'm really interested in 

fundamental questions in science. No, I don't think much about 
it. I've been on boards and I've been a consultant to several 
small companies, but I really haven't contributed much on the 
technical side. If I do any good, it's mostly from steering 
them away from crazy things --but not a lot of that, either. 

Facilities at Stanford 

Riess: Last time we talked about some of the physics faculty at 

Stanford. A couple of others--! don't know whether they're 
relevant, but you didn't say much about the Stanford Microwave 
Lab and Edward Ginzton. 


Schawlow: He was already pretty much out of there. The president of 
Varian Associateshe'd been associated with them from the 
beginning- -but the president was involved in a plane crash and 
sort of didn't have it any more to really lead the company. So 
Ginzton had to take over as president or chairman, I'm not 
sure. By that time he wasn't spending much time around the 
university, so I didn't work with him. 

Riess: Did the microwave lab continue? 

Schawlow: Yes. Oh yes. It's now known as the Ginzton Laboratory. I 
guess somebody gave some money to rename it. It has been 
expanded some and it's a good lab. I worked there for a year 
or so, I think a little more than a year, because the old 
physics corner was very crowded and the new physics building 
was planned, but I think they finished it at the end of "62 or 
'63. And then I had lots of space and moved into the new 
physics building. 

But my contracts were still administered by the microwave 
lab for many years because they had a very good contract 
administration. They also had a very good machine shop, which 
has unfortunately has had to be cut down over the years. They 
had a good drafting department, too, which is all gone. Now 
everybody does their own drawings on their computers. I don't 
think they have any drafting at all. If they have to get 
something drawn, they would send it out somewhere. 

Riess: It sounds complicatedthese little fiefdoms and labs. 

Schawlow: Well, the Ginzton Lab had a building- -it was the microwave lab 
then. Had some good people there. Tony Siegman was there, and 
he wrote several good books on masers and lasers. There were 
some people who had been working on masers and switched to 
lasers. Siegman had some very good students. One of his 
students was Steve Harris, who was so good that they kept him 
on the faculty there and he's done very good things. And one 
of his students was Robert Byer who also is on the faculty. 

Riess: When you came here, it was partly the attraction of the 
microwave lab? 

Schawlow: Well, not really. It was a place for me to work. I never 

worked very closely with any of those people. They were nice, 
and we'd talk occasionally, but they were--. I don't know, I 
was always interested in something different. 


Another one I wondered about was Henry Motz. 


Schawlow: Yes, he had built a far infrared or sub-millimeter wave 

generator using an electron beam. He had left, I think, by the 
time I came here, he retired. I thought it might be 
interesting to do something with that, but people around there 
felt that it was a dead end and they wanted to take it apart 
and use the space. So I didn't push on that. They were good 
people, but I never worked very closely with any of them. 

What I think was more attractive was that they had people 
like Bob Hofstadter and Bill Fairbank in the physics department 
who were doing really outstanding physics. I just wanted to be 
in that sort of an environment, even though I wouldn't actually 
work with them on the same problem. But they were people who 
understood the process of discovery since they had made 
important discoveries themselves. 

Riess: And that was the environment that was really lacking at Bell 

Schawlow: No. They had good physicists at Bell Labs, too. The thing 

that was lacking at Bell Labs was that they wanted to cover a 
lot of fields and do nothing very intensively. It's the same 
thing that Charlie Townes remarks, that they were quite happy 
to support what he was doing, but they wouldn't let him expand 
it. So you could do what you could do by yourself with one 
technician, or occasional collaborations with other people, but 
you couldn't really get a lot of people working on your ideas. 

Riess: What happened to Ali Javan? Did he stay on at Bell Labs? 

Schawlow: No, he went to MIT. He stayed at Bell for a while, then he 
went to MIT fairly early. For some years he didn't produce 
anything. He's still at MIT and has some good work going on, 
but he doesn't seem to getting around to publishing it. He did 
some very good things at MIT. I remember one of the military 
liaison people said that he's a real national resource. 

Riess: I see. You were still at Bell Labs when Ali Javan was there. 

Schawlow: Yes, I was there when he, [Donald R.) Bennett, and [William R.] 
Herriot got the gas laser working. But he [Javan] came in 
there, spent a lot of money right away. He was going to work 
on liquid helium and he bought a cryostat and a big magnet, and 
never used them. He got interested in lasers and had this idea 
of a gas laser and he managed to persuade them to let these 
other two people, Bennett and Herriot, work with him. 

I remember there was a time when the management was getting 
worried. Sid Millman, who was the department head, came around 
and asked me whether I thought this was going to work. They'd 








had some results in measuring some gain, though not for laser 
action. I said, "Oh, yes, I'm sure it's going to work." I 
guess other people said the same thing, so they continued it, 
and it did work. 

In Charlie's book, Making Waves, in one of his chapters he 
talks about the interaction between pure and applied science. 
Last week, when we talked about Stanford, you really made those 
distinctions quite clear here. 

Yet it's nice to be able to move back and forth. I think some 
places they would have called what I was doing applied science, 
but we didn't have to make that distinction. I certainly would 
distinguish between engineering and physics. And in fact, I 
really don't know what applied science is. I think, at best, 
it's just applicable science, science that has some fairly 
obvious application to some problem in technology. Certainly, 
science benefits from technology, just as technology benefits 
from science, so we could get advanced equipment at various 
times. Of course, the rapid rise of digital measuring 
equipment is one example of that, although that didn't really 
come in until the seventies. 

Did you have meetings, 

or tea with your equivalents in applied 

Yes, there was a seminar. For a while, I organized a seminar 
in lasers and a lot of people came to it from companies around 
and that sort of thing. I guess Siegman probably took that 
over. I stopped going to it. We had our own group, people who 
were working for me. We would meet once a week and I would 
have various students talk about what they were doing and have 
discussions there. We did that even at Toronto, and certainly 
Charlie did that very successfully at Columbia. 

But this was a way to get the applied science people together 
with the pure science people? 

That first one was, to get various people together. But I 
think I sort of came to the conclusion that it didn't really 
have a lot to offer me, directly. Of course, in the beginning 
I was interested in everything that had the word laser or 
optical maser in it. I used to collect every scrap of 
newsprint, newspaper, or anything like. But then the field 
just grew so rapidly, you couldn't follow everything; you had 
to realize what it was you were doing and what you weren't 

So I sort of drew back into myself rather than trying to 
communicate with the others. What they were doing wasn't the 


same thing I was doing and my work in the sixties was mostly on 
spectroscopy related to laser material. We did a little bit of 
work with lasers, but not an awful lotusing lasers for 
scientific stuff. 

Riess: I have to ask you whether diamonds wouldn't have been just the 
most perfect thing in lasers. 

Schawlow: Well, they don't work. They have some advantages, but pure 

diamond wouldn't emit light anywhere near the visible or have 
any absorption bands. It's quite transparent way out at the 
ultraviolet. Now, most gem diamonds have various impurities, 
so they will glow. Diamond, I think has been made to lase 
since then. Yes, I think Steve Rand at University of Michigan 
did get diamond to lase. But of course, they're very small and 
their optical properties differ from one kind to another. I 
think they just didn't have the right absorption and emission 
characteristics for lasing action. 

Riess: But they're hard. 

Schawlow: Yes, and that really became apparent, that it was important to 
have something rather hard or it wouldn't stand up to the 
thermal shock when you fired them. 

It was not possible to grow diamonds at that time, and you 
couldn't put in the right kind of doping the way you can in 
sapphire. Artificial sapphires and rubies had been grown for a 
long time and they knew how to put various impurities in them. 

"Science in Action" and Other Honors 

Riess: Why were you chosen as the quintessential scientist for the 
"Science in Action" program? Tell me about that. 


Schawlow: I really don't know why they chose me for the scientist. It 

may be that I had a reputation for being entertaining, being a 
fairly good lecturer, and I had done something important. But 
I don't know. They didn't discuss it with me. And I don't 
know who made the decision, really. 

"Science in Action" was a program produced, I think, by the 
California Academy of Sciencesyou know, the museum in Golden 
Gate Park. Dr. Herrold was the organizer and he was the master 
of ceremonies. They had me on there in January, 1962, just a 








few months after I came. That was the time Frank Imbusch and 
Linn Mollenauer, my two students, went with me and we had a 
crude laser to demonstrate. 

I guess I found that I could break a blue balloon with it 
and thought I would demonstrate that. But the students put on 
the balloonit was a sausage-shaped balloon which was standing 
uprighta hammer and sickle and Sputnik or something like 
that. I was rather horrified but I thought, "Oh well, maybe 
you won't be able to see that." Fortunately, it worked. If it 
hadn't worked, it might 've been bad. But when I saw the 
kinescope later, they had zoomed right in on the thing and you 
could see it relatively clearly. But I didn't emphasize it in 
my talk. 

That was made in the worst possible way for the performer 
because they broadcasted it live and did a kinescope, a film, 
which they then rebroadcast other places. So if you made a 
mistake, it would not only be shown live but would be repeated. 
But I didn't have any feedback on that. That was 1962. By 
late 1965 by that time the show had been running for some 
years and they had decided to have an independent producer 
produce it. He was the one who approached me and asked if I'd 
like to do this. I said okay. He was in charge of it. It 
didn't have any direct connection with the Academy of Sciences. 
They were nearly at the end of their run; I think they were 
going to finish in a few more shows . 

Did it have commercial sponsorship and all of that? 

No, I don't think so. It was on Channel 9 and some other 
educational tv places around. The guy who produced it did get 
an award for it from some national organization, but I never 
heard the details of exactly what the award was. 

I thought it was perhaps like an earlier version of "Nova." 

Also in the early sixties you received the Ballantine Medal. 
And the Thomas Young Medal. 

Yes, and then in '63 I was at a meeting and one of Charlie 
Townes' former students said, "You don't think you're going to 
get a Nobel Prize, do you?" I told him truthfully that I'd 
been nominated but I didn't know. Then in October of '64, the 
university newspeople came and said they'd gotten a tip that I 


was going to get it and share it with Townes and Maiman the 
next day. So they came and took pictures in my class. I told 
the class that I didn't know what it was for, which was not 
true. I then told them truthfully that the last time they'd 
taken pictures in my class, it had appeared in the university's 
annual report as an example of expenditures. [laughter] 

Riess: [laughs] You're good! 

Schawlow: Well, it's true. But then I had a kind of sleepless night. 
Turned out they gave it to Townes--with [Nikolai] Basov and 
[Alexander] Prokhorov, the Russiansfor the maser/laser 
principle. And you can't split it more than three ways. 

After that I thought, well I'm not going to get one. I'd 
stopped worrying about it- -hadn't been worrying about it much 
anywayjust go on and do my thing as best I can. When it came 
seventeen years later in '81 I was surprised to find that they 
had given me a Nobel Prize for contributions to laser 

Riess: Oh dear! Does this make sense, the first award? 

Schawlow: Well, they can only include three, you see. As one of the 
Nobel committee people told me many years later, he thought 
they'd made a mistake including the laser in that. Because 
they could 've given it just for the maser. 

Riess: Including the laser really does include you. 

Schawlow: Yes, yes. So when they gave it to me, in the announcement 

they have some committee member make a little speech. He said 
that the step from the maser to the laser was made by Schawlow 
and Townes, something like that. So I don't know. 

Also, in talking with one of the Nobel people, he said that 
it had been a close thing. It could be that the committee may 
have recommended one thing, but then the Academy may have 
overruled them. They can do that at the last minute. It isn't 
official until the Swedish Academy approves it. But I don't 

Certainly the Russians had been lobbying hard. In fact, at 
the Quantum Electronics Conference in Paris of 1963, Basov came 
up to me and said, "I'd like to discuss with you and Townes who 
in this field should get the Nobel Prize." 

Riess: Was this being funny? 


Schawlow: No. He was dead serious. So I sort of joked and said, "Well, 
I'm pretty sure I know who Charlie Townes thinks should get the 
Nobel Prize"--meaning himself, of course, which he should. But 
I don't know Just what all they did. The Russians do tend to 

I couldn't object. The maser did come before the laser, 
and it was an important step, although what the Russians did 
was less than what Charlie had already done. But they got it 
in print first. Anyway, so I just forgot about getting a Nobel 
Prize. I remember telling peopleseveral times people asked 
if I had a Nobel Prize, and I explained why it had been given 
for the maser /laser principle, that the maser had come first, 
and so I wasn't going to get one. I was pleasantly surprised 
when they did find a way to give me one. They did share it 
with Bloembergen, who had invented the tunable solid state 
maser which was the important one for radar and communications. 
He shared it with me and he was also overdue, I think. 

They do a great job, I think, with the Nobel committees. 
They had this Nobel reunion in 1991 to mark the ninetieth 
anniversary of the Nobel Prize. I was talking there with one 
of the people who had been on the committee when I got mine, 
and I was saying I thought the committee had a great job. He 
said, "Oh well, we made some mistakes." [laughter] 

Riess: It can't help but be somewhat political. 

Schawlow: Well, I certainly never lobbied for it. I was really quite 

Some Russian Physicists 

Riess: The old view of Russia and the Cold War was such that when 
Charlie talked about meeting with Basov and Prokhorov I was 
shocked, or titillated, because the Russians were such 
"nonpeople" to the ordinary citizen of this country. 

Schawlow: Yes, well Charlie tried to make friendly relations with them. 
I think he really believed that the scientist could do some 
good by talking with the Russians, because they could 
communicate on some level. And he was probably right on that. 

We did have some Russian visitors. We actually had a 
couple of Russians work in our lab for a couple of months, I 
guess three months each. We were quite friendly, but I never 
talked about politics or anything like that with them. 






But this country was fighting the Cold War. 
feelings about that? 

What were your 

I never went to Russia. I heard so many horror stories about 
how unpleasant it was. At one point, I got an invitation from 
some ministry of machinery, or something like that, to go and 
give talks and I consulted the CIA to ask how I should respond 
to that. They said, "Write and ask them if you could visit 
some laboratories." And I heard nothing more from them after 
that. But then later there were scientific meetings held 
there. Of course, Basov and Prokhorov did come to the first 
Quantum Electronics Conference, and we met other Russians at 
other conferences-- [V.S. ] Letokhov and Chebotayev were among 

Chebotayev was a very nice person. Everybody liked him and 
he was a very good scientist, too. After the Soviet breakup, 
when things got so very poor, support for science and 
everything in Russia, University of Arizona was trying to hire 
him. I think he had about decided to go there, but then he had 
a heart attack. In fact, he was there visiting and had a heart 
attack, and died. Not very old, fifty-ish I think. 

Letokhov is quite a bright guy, very ambitious, and I think 
quite powerful in Russian science. More of an operator than 
Chebotayev was, but they're both very good scientists. 

And what about the political system, what about communism? 
it the scourge that it was made out to be? 


Well, I never had any doubt about that. I had no use for 
communism, even back in the thirties, I just couldn't see how 
anybody could fall for that. 

It was interesting: at least one of our visitors told me 
that he had read some books here that he couldn't read at home. 
Maybe Gulag Archipelago, I'm not sure. I didn't try to draw 
him out on that because I felt that if I got him into trouble, 
I couldn't protect him. I think some of the scientists did 
kind of incite the people on the other side of the Iron 
Curtain, or the Bamboo Curtain to speak out, and they got their 
heads chopped off. Their scientific status could only protect 
them so far- -not too far. I didn't want to urge anybody to do 
that. I just treated these Russians as individuals. 

I think Charlie had made a real effort to establish good 
relations with them. Peter Franken at the University of 
Arizona did too. I gather since the breakup he's been very 
active in taking money over to help support some of the Russian 
scientists. He says he has travelled carrying big bags of 


money with government permission because there's not any other 
good way to send it. 

Riess: We were trying to get so many of them to come to this country. 

Schawlow: Well, a lot of them did, but there are a limited number of 

jobs, we haven't got jobs for everybody. And I don't think we 
want to destroy Russian science. I certainly have learned a 
lot from Russian science and technology. For a long time they 
were very good in theory, they had a lot of ideas, but they 
didn't seem to have the ability to carry out the experiments as 
quickly as we could. 

Riess: Is that because their bureaucratic structure is even worse than 

Schawlow: It is, and also they didn't have the industry. In fact, I 

asked Gorbachev about that when he visited here. A number of 
us were invited to sit around a table and he would answer 
questionsthey [the questions] were screened ahead of time. 

I asked himrecently there had been a girl from the Soviet 
Union who came to Stanford for an operation. She had a large 
blood tumor that was removed by a laser. From the beginning of 
lasers, as soon as there was anything at all, various people 
had ideas to make instruments. They'd start a little company 
to make them. They hoped to make money. Some of them did, 
some didn't. But it meant that all these instruments were very 
quickly available to us. 

I asked, "Can you do that sort of thing in the Soviet 
Union?" Well, he sort of evaded that. He said, "Well, we hope 
to make things available quickly." But in fact, they built a 
lot more stuff at the laboratories because they did not have 
the instrument industry that grew up rapidly here. They had to 
have much larger support staffs and build things within the 
institutes. The different ministries were insulated from each 
other. I don't think that the Academy of Sciences people could 
talk to the people in the Department of Machine Building, or 
something like that. 

The compartmentalization of Soviet science was a big 
drawback, I think. If they really put the money into something 
like the space program, then they'd build everything within 
that organization and could do very well. But for independent 
science- -they did have much larger staffs than we did, but they 
didn't have all the marketplace to draw on that we had. 


Riess: Did scientists there have the same kind of liaison with the 
government that Charlie describes when he was on the science 
advisory panel? Do they have that in the Soviet Union? 

Schawlow: I'm not sure how they do it. They have this Academy of 

Sciences which is quite different from our Academy. It's very 
powerful, it runs a lot of institutes, has it's own budget, 
where our academy is strictly an honorary thing- -it can do 
studies, but no more. "Le'-to-khov"--or "Le-t6'-kov" because 
in Russian it's "Le-to'-kov," but he says that when he comes to 
the west it's "Le'-to-kov," because we tend to put the accent 
on the first syllablehe mentioned meeting with Brezhnev. So 
the favored scientist did have access to quite high officials, 
but I don't know the details. 

I know Basov became very powerful. Apparently there was 
some power struggle between him and Prokhorov, and he became 
head of the Lebedev Institute, which is a very large institute 
for research on electronics and then lasers. After that, 
Prokhorov got his own institute, the General Physics Institute, 
and he had a large group. I noticed one year his name was on 
more than twenty papers; I'm sure he didn't do all of those 
himself, but he had a big group working. They both did some 
nice things. They're both very capable people, and a lot of 
the other Russian scientists are too. 

Anyway, I think it was a good thing that people like 
Charlie feel that they need to keep in touch with the Russians 
and build bridges as much as they can. But I didn't feel it 
was something I could do. 

Riess: That reminds me of the state of physics in Russia at the end of 
the Cold War. Have you brought Russian physicists to Stanford? 

Schawlow: The department has. We have a theoretical astrophysicist, 

Andre Linde, who is very distinguished, and his wife who is a 
nuclear physicist. They have been added to our faculty. I 
don't know, there are probably others around the place too, but 
I don't know for sure. But I haven't been in a position to 
find jobs for anybody. 

There are a number of Russian scientists around various 
places, but we have only the two. Ours is a very small 
department compared to most other major physics departments. 


People and Projects 
[Interview 7: November 14, 1996] ## 

Optical Science 

Riess: So much of your work has been taken up by people in the field 
of optical science. What do physicists think of the optical 

Schawlow: The physics community thought of optics people as being lens 

grinders-- [chuckle] a lot of them were. The Optical Society is 
a very diverse mixture of people, a lot of people interested in 
vision, and some in color imagery. And oh my, those people 
were fussy about terminology. You had to use the exact proper 
terms, and they didn't always agree on which ones they were. 

Mary Warga was the executive secretary of the Optical 
Society. She had been a professor at University of Pittsburgh 
and had worked in spectroscopy, I think analytical 
spectroscopy, I'm not surethat is, analyzing compounds, or 
alloys. However, she was full time with the Optical Society 
and when the first lasers operated she really went after them 
to get the laser people into the Optical Society. She came to 
Bell Labs and visited with a number of people there. 

She got Maiman to give a talk at the first meeting that 
they held after his announcement --on very short notice, but she 
did it. Then they had another meeting in Pittsburgh in the 
following spring and a lot of invited papers on lasers. I 
gather some of the old line optics people got rather annoyed at 

Riess: It's interesting, you say with a smile that they were lens 
grinders. At the same time the question of coherent light, 
must interest people in optics. 

Schawlow: Well, of course they didn't have sources of coherent light 
before that. 

Emil Wolf at the University of Rochester has done a lot of 
theoretical work on partial coherence of light. You can get 
it. After all, the famous Young experiment which sends light 
through two slits and has them interfere on a screen some 
distance beyond that, really requires that the light reaching 
the two slits be somewhat coherent. They've done that since 
Young's time which was the early 1800s. Every undergraduate 
physics course does it. 


But the way we always did it was that we'd use a small 
source, have a narrow slit in front of the source, have a 
filter so that you'd get a narrow range of wavelengths. Then 
the light reaching the second pair of slits, which was maybe 
several meters away, would be only waves that are going almost 
entirely in one direction. So they would have a plane 
wavefront and they'd be coherent, nearly enough, across the two 
slits. So you'd get partial coherence. 

With the laser we had a source of coherent light which was 
something quite different. And that stimulated a lot of work, 
a lot of physics questions in connection with lasers. It also 
suggested a lot--I didn't get into that much, but it did 
suggest interesting studies of materials related to laser 
material. There "d been work on that for many years in physics, 
and chemistry. Again, not a forefront sort of thing, but it 
interested me when I got interested in lasers. Actually the 
first nine or ten years that I was at Stanford, that was really 
the main focus of what we did, at least a lot of what we did. 

For instance, I had found at Bell Labs that the extra 
lines, so-called satellite or neighbor lines, in the spectrum 
of ruby were caused by chromium ion pairs. Looking at the 
crystal structure, you could see that there were a number of 
different sites, that the neighbor could be in different 
directions. It could be right along the symmetry axis or off 
to one side in various directions. 

Mollenauer, Imbusch, Emmett, McCall 

Schawlow: I got Linn Mollenauer to work on trying to unravel that by 

applying stress to the crystal, just putting a weight, a piston 
pushing on the thing. We could see the line shifted in various 
ways. The direction in which you get the maximum shift would 
be along the direction of the particular pair. 

Mollenauer was actually my first student and has done very 
well at Bell Labs. He worked for a while as assistant 
professor at Berkeley, but then he went to Bell Labs. He's 
done a lot of work on optical solutions which are very good for 
long-distance high speed communication over fiber optics. 
They're a serious competitorthat they may be the system of 
the future, although there are other competitors. But they've 
shown remarkable results. 

Riess: You came to Stanford planning to work on spectroscopy. 


Schawlow: Mostly that. I don't know, there wasn't anything very 

systematic. I attracted a lot of students. When I came I 
attracted students really too fast. I hate to say no to 

I gave them various problems that occurred to me. We were 
kind of exploring. I should mention that somebody asked me, 
about the time I was coming here, how I was going to compete 
with Bell Labs when they had so many good people working on 
lasers. I said, "Well, it's simple. I won't compete. I'll do 
something different." That may have been part of the reason 
why I didn't really work on trying to find new laser materials 
and instead I worked on trying to clear up some of the physics 
questions that were suggested by lasers. 

Riess: Did you finish talking about the chromium ion pairs? 

Schawlow: That was one of the things we did. Gosh, my memory begins to 
fail me. I have a time remembering exactly what each student 
did now, some of them, although I can remember most of them. 
Frank Imbusch was the second student. 

Mollenauer and Imbusch had been working with George Pake, 
but Pake was leaving- -he went to be provost at Washington 
Universityso they asked to work with me. Imbusch was from 
Ireland, and is back there now, at the University of Galway. 
He was very good at getting things done. Mollenauer was rather 
slow, but deep. He always saw things a level deeper than I had 
thought about them. But Imbusch was quick for getting things 
done, and so we did a number of "Oh, let's try this out" kind 
of experiments. 

Riess: Would it happen in the lab or would you sit around? 

Schawlow: We would have meetings every week, a group meeting to discuss 

things. I would talk to the students some, go around and visit 
them in the lab or they'd come and see me to discuss what they 
might do next. Mostly they had a lot of freedom to do pretty 
much whatever they wanted to. 

I guess mostly I would ask questions and sometimes make a 
comment, a suggestion. I'd have these seminars, group 
meetings, and have the students talk. I would ask "dumb" 
questions once in a while to make sure that other students 
there understood what they were saying, and perhaps even to 
clarify their own thinking. I was really not ashamed to ask 
stupid questions because I knew that other students in the 
group were working on different things and they didn't know. 


Then, one student came along, John Emmett, the red-headed 
guy in the movie ["Science in Action"]. He had come from 
Caltech and apparently had a sort of checkered reputation 
there. He'd done very well at the things he was interested in, 
and not bothered with other things. However he'd gotten 
through all right. 

He was really a strange one in some ways. Once he sort of 
disappeared for some months. I didn't see him, so when he 
reappeared I asked him to give a talk at our group meeting. It 
turned out that he had his own machine shop at home and he was 
building parts for a big laser. 

He knew more about flash lamps, I think, than anybody else 
in the worldthe kind of flash lamps used for pumping lasers. 
In fact, Elliot Weinberg, who was our contact with the Office 
of Naval Research, put in some extra money to support Emmett 's 
research, and Weinberg took Emmett with him to Europe to visit 
various laboratories where they were working on laser 
f lashlamps . 

He really liked to build things, Emmett did, and he built a 
big powerful ruby laser. It was rather expensive work, even 
with the Navy money it was very expensive, the things he did. 
He built a high-powered ruby laser which used a rod of ruby 
that was something like six inches long and three-quarters of 
an inch in diameter. I think they cost about two thousand 
dollars each. They're, of course, synthetic ruby. 

The way he was using them they produce ultrashort pulses 
that would only last a few nanoseconds. I figured these rods 
would get destroyed by the high powered light flashes in maybe 
a thousand flashes. I think there are about a thousand 
flashes, each about two nanoseconds, so we'd get about two 
thousand nanoseconds out of this $2,000. 

It was costing us about a billion dollars a second to run 
this thing and I told him that. He said, "Gee, boss, I realize 
that I've been here a couple of years and have only done a few 
microseconds of real work." I said, "I've been suspecting 
something of the sort." [chuckles] 

It was very hard to get Emmett to actually measure 
anything. Elliot Weinberg wanted him to measure whether 
flashlamps were opaque to their own radiation in the reddish 
sort of region that was used particularly for pumping neodymium 




gas lasers and neodymium YAG lasers. 1 Emmett had the apparatus, 
and set it all up he could have done it better if he'd had 
another laser to probe the absorption of the discharge, but he 
used a short flash lamp, a very clever thing. 

Weinberg came in on Saturdays to make Emmett sit down and 
actually take the measurements. That's why I put Weinberg 's 
name as coauthor on a paper sponsored by NASA, even though he 
was working for the Office of Naval Research! 

Emmett told me years later that he really didn't want to 
finish anything. He was afraid if he finished anything I'd 
make him leave, and he was just having too much fun there. 

It makes me think of George Devlin, another clever scientist 
you worked with. Is that a question: whether or not it is 
important to make them into well-rounded physicists or whether 
that's even within their capacity? 

Well, you try and get them to do what they can do. 
them as well-rounded as you can. 

You make 

Emmett, after he left us, went to the Naval Research Lab in 
Washington and worked on high powered lasers for a while. Then 
when Livermore was starting to get into big lasers for nuclear 
fusion he went there and eventually became the associate 
director in charge of all their laser programs at Livermore. 
After some years he left there and started a business which I 
gather he sold and made a lot of money and is doing various 
consulting. A very clever guy, but it was sort of like having 
a tiger by the tail, a nice tiger, but-- [chuckle] --a tiger. 
You really couldn't control him. 

I wanted to explore various things. I got interested in 
the far infrared region which was still a big hole that hadn't 
been bridged really. We jumped from the microwave right to the 
visible and near visible. I had one student build a big far 
infrared spectrometer and I actually bought a gas laser using 
cyanide gas. 

1 [from Interview 5] I probably ought to admit it, that was one of my 
big mistakes. Professor Dieke at Johns Hopkins had been working on spectra 
of rare earth ions and crystals, and he told me that I ought to try 
neodymium. I looked at the spectrum and thought, "Oh, that's awfully 
complicated, that doesn't look very promising." But other people did, and 
neodymium is still one of the best ions to use. You can't put it in 
sapphire, but you can in a lot of crystalsand in glass, too. But I 
didn't try it and others discovered that independently. [Schawlow] 






That's a funny story. It turned out what they were using 
was methyl cyanide which is a liquid, and as such is not too 
poisonous. But if you're going to vaporize it as you would in 
gas lasers, you have to have good ventilation, which we did. 

But it turned out that Emmett had been using acetonitrile 
as a liquid to measure the energy of his laser pulses. He put 
it in a flask with a tube coming up that measured the expansion 
when a laser pulse struck it. It turned out that acetonitrile 
was methyl cyanideit's the same stuff. 

We thought originally that this laserthe people who 
invented it thought it used the CN radical, and that would have 
a magnetic moment, so it could perhaps be tuned by applying a 
magnetic field. But by the time we really got under way, other 
studies had shown that it wasn't that, it was the HCN which was 
produced somehow in the discharge, another really nasty gas, 
but that is not a free radical and wouldn't be magnetically 
tunable. So nothing much came of that. We did some work on 
tuning the thing as much as you could by going to different 

Bruce McCall was a student who worked with that, and McCall 
was an unusual one. He started out with me. He came from a 
fairly wealthy family, of auto parts manufacturers in the 
Detroit area. He was wrestling with the question of whether he 
should go instead to the business school. He was admitted to 
Harvard Business School and he went there and got an MBA, but 
he came back. He finished working on this cyanide laser. 

He later started his own company, Molectron, which wasn't 
terribly successful, except that he eventually sold it at a 
good price because they had begun to develop a device for using 
lasers for treating stomach ulcers. Cooper Laboratories was 
sort of collecting laser medical companies, so they bought this 
at a good price. 

This was still in the sixties or was this in the seventies? 
It was probably in the seventies when they had this company. 

Seems like something people might have been tempted to do a lot 
of, grabbing at something, turning it into a company, and into 
a profit. 

Yes, but I don't think that was his intention. He did make 
infrared detectors, and the detector part was spun off by 
Cooper Labs. There is now still a Molectron detector company, 
but he has nothing to do with it. They made lasers of various 
kinds, but they didn't sell very many of them, I don't think. 


And it was sort of just scraping along until they started on 
this medical thing, and that was salable. 

Riess: When you have an idea, like the methyl cyanide, do you have to 
know where you're going to go with it? 

Schawlow: Emmett was using it just as a liquid that had a fairly low heat 
capacity and would expand when the laser pulse hit it, just as 
a kind of thermometer. But when we bought that cyanide laser, 
I thought that it worked with the CN radical and that it could 
be tuned by magnetic field. That turned out to be wrong, so we 
just did a little more exploring of its properties and closed 
that off. 

Titanium in Ruby Rods 

Schawlow: We built a far infrared spectrometer. We used that for 

studying crystals, looking for lines from ions in crystals. It 
was related to the work that we'd been doing in the visible 
region. Some of these ruby lines were separated by intervals 
that would correspond to transitions in the far infrared 
region. We tried to see whether they really were from the same 
pair of ions or from different pairs, whether they just 
accidentally happened to be near each other. 

In fact, we had originally reported that they were from 
the same one, but we were beginning to doubt that. And we did 
get a big rod of dark ruby, about six inches long, and looked 
through it, and the particular line we were concerned about was 
not there. So we looked at crystals with other transition 
metal ions, trying to see if it was an impurity, things in the 
iron series, like titanium. Well, we got a crystal of titanium 
and there was that line. 

A few years later we had a visit from a man named Otto 
Deutschbein. Deutschbein must have been German originally. He 
had written his Ph.D. thesis in the early thirties. He had 
done a lot of work on the spectrum of ruby and other crystals 
related to it with these transition metal ions. We told him 
about this, that this line turns out to be titanium rather than 
chromium. And he said, "That's interesting." By that time, he 
was at the French Post Office, which is the big communications 
lab in France. 

He said, "You know, it's interesting. Djevahirdjian in 
Switzerland has made a lot of ruby rods that are used in lasers 
in Europe." He had sent samples of his rods to the laboratory 


at the French Post Office, and they had found titanium in them 
and they reported that to Djevahirdjian, and he said, "Oh, 
goodness! Don't tell anybody. That's my secret." The 
titanium helps the crystals grow better into the large 

Riess: You might decide to just go through every material and come up 
with similar kinds of data about it. 

Schawlow: It would have been better, actually. We had crystals of 

titanium-doped sapphire, and this turns out to be a very good 
laser material. Well, we didn't even try it as a laser 

Riess: So that wouldn't be an approach? 

Schawlow: It could have been, but we didn't. I don't know, I was very 
opportunistic, I just sort of tried various things. I really 
wasn't well focused, didn't plan, wasn't systematic. I just 
tried whatever happened to look interesting at the time. 

Riess: There is something about the process here that makes me 

curious. Whenever you have an idea, you need to get money for 
it, and you need to write a proposal? 

Schawlow: No. I would only work with the things that were vague enough 
that I could have a good bit of latitude to do what I wanted. 
Even when I did propose something fairly definite, if I did 
something different they would accept it in those days. So I 
just didn't write special proposals for each project. I never 
really had enough money, but I managed to scrape by on what we 
had. I had very few postdocs because I really felt I couldn't 
afford them. But we had some. 

We did do some things on rare earth ions in crystals. In 
fact, I had a student working on crystals with praseodymium and 
lanthanum fluoride. I was consulting with Varian Associates, 
and they had somebody there who liked to grow crystals of 
lanthanum fluoride. He gave us some samples with various rare 
earth materials in them and we did various things with them. 

Many years later, I had another student who was doing some 
work with that, which was suggested not by me but by a postdoc, 
Steve Rand. And I went to look up some information about this 
crystal and I was rather surprised to find that my name was on 
a paper back around 1963 about this very crystal. The work had 
been done though mostly by Bill Yen, who was a postdoc, and by 
that time was a professor--f irst at Wisconsin and then the 
University of Georgia. 


Riess: Yes, he's a contributor to this book dedicated to you, isn't 

he? It says he joined the Schawlow group in the summer of 1962 
as a research associate, "increasing the size of the team to 
four." 1 The four would have been Imbusch, Mollenauer . 

Schawlow: Somewhere around there I got Warren Moos from Michigan. 

These people sort of were offered to me. At that time, I 
was still just kind of drawing on the money that was available 
in the microwave lab, not really worrying about budgets yet. 
Then I began to get my own contracts and had to worry about 
budgets . 

Light-Controlled Chemical Reactions ft 

Schawlow: There are two things I should mention. As you've probably 

learned from Charlie Townes, one of the things that stimulated 
my interest in how to get sources of shorter wavelengths, and 
also brought me to Columbia, was the Carbide and Carbon 
Chemical Fellowship, which had been started by Helmut Schulz. 

Schulz had a vague idea that you could control chemical 
reactions by light of some wavelength between far infrared and 
visible. That was really the only application that we had 
vaguely in mind when we were working on the idea of a laser. 
So I thought I would like to do something on that. 

I got one student, Bill Tiffany, to try and study a 
reaction that might be stimulated by a ruby laser, which was 
essentially the only laser that we had, really, in those days. 
We tried looking at reactions in bromine with ethylene, I 
think. We found that you could tune this laser by changing its 
temperature. As you scan across the spectrum, a lot of lines 
are drawn in the bromine, but when you're on a line you could 
get a reaction. If you're off a line, you wouldn't get a 
reaction. So it could be isotope-selective. 

In the end we didn't get any separation. There were fast 
chain reactions that scrambled the isotopes before we could 
extract them. Actually, chemists knew about that sort of 
thing, but we didn't. So in the end, we did initiate the 
action selectively, but we couldn't complete it. 

1 Lasers, Spectroscopy and New Ideas, A Tribute to Arthur L. Schawlow, 
Editors, W.M. Yen and M.D. Levenson, Springer Series in Optical Sciences, 
Volume 54, Springer-Verlag, 1987. 

Riess: Did you consult with chemists? 

Schawlow: Only to get the samples analyzed. I don't think there was 
anybody there [in the chemistry department] who was 
particularly interested in this sort of thing at the time. 
They did use a mass spectrograph to analyze what we were 

However, after Bill Tiffany finished, I couldn't find other 
students that wanted to work on chemistryit wasn't physics, 
it was chemistry. I also began to have qualms. It would be 
okay to separate bromine isotopes, but if anybody found an easy 
way to separate uranium isotopes that would be a real disaster. 
So I decided I just wouldn't work on isotope separation of any 
kind, because I might have a good idea that made it easy, and 
that would be terrible. 

Riess: You never published? 

Schawlow: We published what did on the bromine, but we didn't do anything 
further. What I know now is that you really have to do those 
things fast. There's a lot of work done on laser isotope 
separation. Indeed, if they ever need to separate more uranium 
isotopes they would probably build a plant using lasers to 
separate it, rather than the diffusion or mass spectrographs 
that they used before. Livermore did a lot of work in that 
later. There was some done at Hanford, too. 

It's okay for the government in their big secret labs to 
work on that sort of thing- -anyway, I thought it best that I 
just not touch it. The way they do it is not easy. It's quite 
difficult. On the other hand, Dick Zare has done work 
separating chlorine isotopes. That's apparently very easy. If 
it were as easy to do in a garage, if it were that easy to 
separate uranium isotopes, that would be a disaster. 

Riess: These issues and concerns make me thing about the Pugwash 
conferences. Did you attend them? 

Schawlow: No, I never did. Never got involved, never got invited. I 
think we talked before about how I really kept out of 
government stuff, largely by refusing secrecy. I think, also, 
I was spending an awful lot of time with Artie and with my 
classes and my students and so on. I just didn't have any 
energy left over to do those things. Probably I didn't get 
invited because I wasn't involved with the government. If I'd 
been asked, it would have been hard to refuse. But fortunately 
I wasn't asked. 

Consultancy at Varian 

Riess: Also, consulting with Varian. Was that ongoing? 

Schawlow: No, I gave it up after a while. I had become a director of 

Optics Technology, which was a struggling little company run by 
a man named Narinder Kapany. He was a Sikh who had gotten a 
Ph.D. at Imperial College, London. He was a man with a lot of 
ideas, but it was a badly run company I'm afraid, which I 
couldn't do much about. They had a lot of clever ideas, and 
every year he'd have a different product which had a different 
market. So they lost money and eventually went bankrupt. 

But he wanted me to consult with them full-time at a time 
when things were prosperous. And I felt the Varian thing 
wasn't getting anywhere. They didn't have a real commitment to 
basic research. Several times they decided they were going to 
make gas lasers, and then decided they weren't, so I didn't 
feel that was really very interesting. 

Riess: What do you do, as a consultant? 

Schawlow: You just go over there and they tell you what they're doing. 
Maybe they ask some questions. Maybe you can answer them, 
maybe not. 

Riess: You might have a number of consultancies? 

Schawlow: Could have, as long as they didn't conflict. At one point, 

Hewlett-Packard wanted to start making microwave spectrographs 
and wanted me to consult. I felt that that wasn't fair because 
that might compete with something that Varian was doing. I 
mean, they're both in the instrument business. So I didn't 
take that one. But I could have done things that were not 

Riess: When you're on a board of a small scientific company, don't you 
end up being a scientist on that board? 

Schawlow: Sometimes, yes. Sometimes you make technical comments and 
sometimes you come in and talk with people in the lab 
occasionally. But in principle, the board has to set policy. 
Kapany was a strong leader and I really don't think I did much 
good. I think I sort of wasted my time. Ended up making no 
money at all. 

Riess: Did Stanford make policy about how physicists were or were not 
to be involved with the larger community? 


Schawlow: The had some policy, I think largely driven by the engineering 
department where they had some professors that were running 
companies at the same time. I think they had a rule that you 
couldn't spend more than one day a week on the average 
consulting. I spent a good deal less than that. 

I'm afraid that I don't think I really did anybody much 
good with my consult ing- -maybe helping them avoid making some 
mistakes. I don't know, their problems just didn't really turn 
me on very much. 

The Hodgepodge of Projects, Ray Guns, Full House in The Lab 

Riess: You were very engaged in what you were doing in those years, 
the sixties, at Stanford? 

Schawlow: Yes, I was enjoying it, it was interesting. I didn't think the 
individual projects were terribly exciting to people in other 
branches of physics. 

Much of our work was exploring the spectroscopic properties 
of transparent crystals containing rare earth ions. Many of 
the lasers existing then used these crystals, among them ruby. 
The spectra are the raw materials from which you may be able to 
make lasers or other devices. We didn't have widely tunable 
lasers yet, and so we worked mostly with high- resolution 
grating spectrographs. 

Sometime in the late sixties, Roger MacFarlane joined us. 
He had obtained his Ph.D. in New Zealand, and knew much more 
than I did about the theory of these spectra. He was also a 
good experimentalist, too. After about two years with us, he 
went to the IBM research laboratory in San Jose, California and 
is still there. He has done very nice things through the 
years, and collaborated with us in the 1990s when we once again 
turned our attention to ions in solids. 

One thing that did happen in our lab- -I wasn't really the 
initiator, it was a man named Robert White, an assistant 
professor, who suggested that they look at manganese fluoride. 
Manganese fluoride is an anti-ferromagnetic material at low 
temperatures. That means that instead of all the electron 
spins being lined up parallel as they are in a ferromagnet, 
they are lined up anti-parallel. But there could be spin waves 
in this thing. White suggested that students look for spin 
wave side bands, and indeed, they found them. That was quite a 
nice thing and it surprised a lot of people. 


Somehow, I felt that what we were doing was kind of a 
hodgepodge of stuff in the sixtiesbut each one was fun. I 
did get invited to give the Richtmyer Lecture at the joint 
meeting of the American Association of Physics Teachers and the 
American Physical Society in 1970, I think. I chose for that a 
title, "Is Spectroscopy Dead?" Laser spectroscopy hadn't 
really begun yet. 

I remember asking various people what they thought--! asked 
colleagues if they had ideas. Felix Bloch came right to the 
point. He said, "What do you mean by dead?" I said, "Oh, 
turned over to chemists." [laughter] That had happened to 
microwave spectroscopy. No physicists were working on 
microwave spectroscopy after our book came out, I think. That 
pretty much killed it. Everybody thought, "Well, it's all 
done. All the physics is done." But the chemists were more 
interested in looking at a lot of different molecules with 
microwave spectroscopy. 

Riess: Chemists, or physicists who are interested in chemistry? 

Schawlow: Usually they were chemists who were interested in the physics 
of things. 

So, anyway, this was a great honor. I didn't give a very 
good talk, and I never did get the manuscript written up, which 
I was supposed to do. I had the flu- -I got the flu when I went 
to this meeting in Chicago. It turned out that Luis Alvarez 
had been president of the American Physical Society, and he was 
supposed to give his retiring presidential address. But he had 
the flu so bad that he couldn't give his address, so I was 
allowed to ramble on a little beyond my allotted time, [laughs] 
But I had the flu and I was not feeling well at all. 

They said that Alvarez was there and was being attended by 
his famous father you know, Walter Alvarez, a very famous 
doctor at the Mayo Clinic. Although what we had done was 
rather hodgepodge, people thought it added up to something. 

[looking through a list of his publications] We were 
starting work on measuring the position and width of the 
spectral lineswith Imbusch, again, and some people at Bell 
Labs. I guess that was after Imbusch had gone to Bell Labs. 
He was there for a couple of years. 

Riess: I imagine that all of this writing of papers took a huge amount 
of time. 

Schawlow: It does, but in many cases a student or a postdoc would do some 
of the work. 




I see there's one here about a portable demonstration laser 
that I wrote. Ken Sherwin had made my ruby ray gun and I was 
getting a lot of inquiries from high school kids who wanted to 
make a laser. I offered it to Popular Science, and just about 
the time I got the answer back, 1 got a letter from some woman 
in San Jose complaining I was giving dangerous toys to 
children. Of course, this was a toy housing I'd used, it 
wasn't at all a toy. 

Then they [Popular Science] wrote me and said they had 
another article about making a laser, but they would buy my 
article for two hundred dollars and not publish it. I thought, 
"Well, maybe it's better not to publish that." They were 
offering, however, to send more detailed instructions on how to 
build a ruby laser. I gather that those instructions changed 
over the next few months so it became more and more what we had 
in our paper! [laughs] 

Then I had the cute experiment about measuring the 
wavelength of light with a ruler, where you just have a laser 
beam skimming along the surface of the laser, being diffracted 
from the rulings at an almost glancing angle. 

Where did you publish that? 

That was in the American Journal of Physics, which is the 
journal of the American Association of Physics Teachers. 

So that might be useful as a demonstration. 

Oh yes. I think a lot of people have used that. 

[looking through papers] Oh yes, we studied strontium 
titanate, which is a ferroelectric material, with chromium as 
an impurity. We tried to see if we could change the intensity 
of the fluorescence by putting on an electric field. We 
eventually got a small effect. (That was done with Stan 
Stokowski. ) 

The idea was that you deform the crystal enoughsee, the 
chromium ion, if it were at a perfectly cubic surrounding, it 
wouldn't be able to have any electric dipole emission at all. 
But because it's not at a center of symmetry, it has an 
electric field which deforms the ion and makes it possible for 
it to emit. So the idea was to apply an external electric 
field to deform this rather deformable material, strontium 
titanate, and see if that would change the intensity. We did 
succeed in that. 


Let's finish this [review of the students and postdocs] 
off. You know, we had all the students I could handle. At one 
point, I had ten students and I told them I'd never given a 
Ph.D. Well, after that they started coming out the pipeline. 
But in 1968 I think, I had some contact with Dick S lusher who 
was getting his Ph.D. at Berkeley with Erwin Hahn. He had a 
National Science Foundation postdoctoral fellowship. He wanted 
to come, and it wouldn't have cost me anything, but I talked 
him out of it. I was feeling rather despondent at that time. 
We didn't have any room, we didn't have any money to spare. 

Riess: Here? 

Schawlow: Yes. 

Riess: You had your ten rooms? 

Schawlow: Yes, but they were all full of students. Especially, we didn't 
have any money to start anything new. I suggested that if he 
wanted he could come, but maybe it wasn't too good an idea. So 
he went to Bell Labs instead and did very well. 

He got the Schawlow Prize from the American Physical 
Society Laser Science Group a year ago, and I was there to tell 
the story of how I foolishly missed a chance to have him work 
with me. But I was just, well, feeling kind of depressed and 
not having any thrilling ideas, and really not having much 
freedom to do new things . 

Riess: That's the part I don't understand, not having the freedom. 

Schawlow: I didn't have the money, really, to start something that would 
require a lot of new equipment. I had good spectrographs of 
several different kinds, but--. 

Riess: But this is the drying up of money time or what? 

Schawlow: Yes. It was around that time that NASA decided they couldn't 
continue to support this work. They were under pressure to do 
things that were more closely related to their missions. So 
they said they were not going to be able to support me any 
longer. The Army Research Office had been giving me small 
amounts, $30,000 a year. It was a little later that they 
dropped out . 

At any rate, I felt, "Well, I could go on doing the same 
sort of thing, but I couldn't really start anything very 
different." So I didn't encourage him to come although I would 
have taken him if he decided he really wanted to. 


Fortunate Conjunction 


Schawlow: Then there's something, and I don't know whether I ought to say 
it or not, but I was on the Physics Advisory Panel of the 
National Science Foundation. They started a new program, 
offering equipment grants. And the next year's meeting, Wayne 
Gruner, head of the physics section, said, "Well, we haven't 
been getting many applications for those grants." I said, 
"Well you've got mine." He said, "Oh really? Do we?" And 
not very long after that I got the grant. That was a very 
fortuitous timing, because it came just about the time that Ted 
Hansch came here. 

Now, again, I was not really too interested in taking him 
on, but I got this letter from Peter Toschek, whom I had met. 
He wanted to know if I could take this man as a postdoc. I 
wrote back and said that I didn't have any money and he said, 
"Well, would you take him if he'd get a NATO fellowship?" I 
said, "Oh, all right." He did get that, and when he arrived, 
it was a very small fellowship. When we saw how good he was, 
we found another hundred dollars a month or so to help him. 

Riess: You had met him before, hadn't you? 

Schawlow: Well, he told me that, but I didn't remember that I had met him 
at a conference in Edinburgh. But I'm very bad about that sort 
of thing. 

Riess: As a side note, it seems to me one of the pleasures of being a 
physicist was the far-flung conferences. Because of your 
responsibilities to Artie, did you miss out on that? 

Schawlow: Well, not really. We felt we could go away for a week or two. 
By that time, Artie was living away from home. We went away 
for sabbatical in 1970, and that was bad, because while we were 
away the people in the house he was living in decided that they 
couldn't handle him any more. There were young girls, high 
school age or so, there who were afraid of him. He was big and 
strong, and he was having tantrums, though he wasn't hitting 
anybody. That was bad. If we'd been here, maybe we could have 
soothed them. But we had to find another place for him. 

Riess: Where did you go on that sabbatical and what did you do? 


Schawlow: We went to London and I actually was ant i- commit ing to Redding. 
My good friend George Series was there. I didn't really work 
on anything much; I think I did a little study of possibilities 
for x-ray lasers, but I didn't really reach any very valuable 

I think I foolishlywhen you go to a country like that, if 
people know you're there they invite you to give a lot of 
talks. Doesn't seem like an awful lot for each one, but in the 
end it was too much. 

Riess: Too much to get any physics done. 

Schawlow: Yes. That's right. 

Riess: That must have been when you met Ted Hansch. 

Schawlow: It may have been a year or two earlier, I'm not sure. 

I remember very wellwe flew to London and rented a car, 
which was a tiny Fiat, and drove up to Edinburgh. That was a 
nice adventure. With that car you really sort of had to stop 
every hour because it wasn't very comfortable. I think it was 
a deal that Pan Am had the car rental was included in the 
excursion fare. 

Riess: Did you have your daughters with you? 

Schawlow: Not on that occasion, that was just a week or two. When we 

went to the sabbatical, yes indeed. They went to the American 
School in London. One of them, Edie, the younger one, was 
involved in two amusing stories there. She told someone, I 
don't know if it was another student or a teacher, that her 
father had invented the laser. The teacher said, "Oh, I didn't 
think so. Got to ask the science teacher." 

The science teacher said, "Oh no. The laser was invented 
by a Mr. Laser, I think it was Samuel Laser." She was sort of 
crushed, but I managed to find a magazine or book that had the 
facts, [laughter] 

She was eleven at the time. They had a long weekend for 
the American Thanksgiving, so we all went to Paris. She 
complained later, everybody else had a holiday but she had to 
go to Paris. In later years she thought that was funny. 

[tape interruption] 


Ted Hansch and Edible and Tunable Lasers 

Riess: Ted Hansch came to Stanford In May, 1970? 

Schawlow: Yes, he came before I went on my sabbatical and he did some 
wonderful things, including when I was away. He was very 
generous about putting my name on things when he'd really done 
most of it. He was just a genuinely nice person, good sense of 
humor, as well as being a wonderful physicist. He had good 
hands and could build things himself very quickly- -which I 
could never do. Also, he was good at theory. 

Riess: Did he arrive with something that he was working on? 

Schawlow: He had worked on gas lasers for his Ph.D. thesis, but he was 
willing to work on anything that looked interesting here. I 
can't remember the exact sequence, but I think we got that 
equipment grant just before he arrived, and he helped us decide 
what it was we were going to buy and I decided to buy two 
lasersyou could then get them commercially. One was a 
nitrogen laser which gave short pulses, but they were a hundred 
kilowatts, a hundred thousand watts. They could pump all sorts 
of dyesdye lasers had been discovered, but they hadn't been 
used for much. 

One of the first things Ted did was to find a way to make 
this dye laser fairly monochromatic. One of the advantages of 
dye lasers was that they were tunable, but their output tended 
to cover a rather broad wavelength band. Whereas for 
spectroscopy you want them to be fairly monochromatic so you 
could tune them across spectral lines and see fine details. 
He was able to make a pulsed laser that was fairly 
monochromatic, and it was pumped by this nitrogen laser. 

This nitrogen laser also was used we had some fun playing 
with various dyes because almost any dye that glowed would 
lase, and even the gelatin filters, the photographic filters, 
would lase. So then 1 had one of the most fun experiments 1 
did, about the last time I did anything with my own hands. I 
decided, well, if you can put dyes in gelatin, maybe ordinary 
Jello would lase. And it didn't. I tried all twelve flavors 
of Jello and they didn't fluoresce very well. I guess people 
don't like fluorescent foods, [laughing] Many of the dyes that 
fluoresce are poisonous anyway. 

But I realized there was a dye that wasn't poisonous, 
namely fluorescein, because dentists paint that on your teeth 
to show up the plaque. So I put some fluorescein in some Knox 
gelatin and managed to get laser action in that. So we 


published this and put in a phrase that this is the world's 
first edible laser material. [chuckles] That's often been 

Riess: That's more comic strip material. 

Schawlow: It is, but it turned out to be something very useful that we 
didn't realize. Even before we publishedwe weren't 
secretive, but somehow somebody at Bell Labs heard about this, 
maybe had a preprint, and they realized that photographic 
plates used gelatin and it could diffuse dyes into the 
photographic plates, so they could put patterns on there, like 
diffraction gratings, and could tune the laser with the pattern 
of lines on the photographic plate. Lines one behind the other 
would act as a grating, depending on the spacing of them. So 
they published that. 

And then people with semiconductors began to put gratings 
of that kind in their semiconductor lasers to help tune them. 
Something quite serious came out of this fun experiment with 
the edible laser. You never know what will come from research. 

Hansch had this tunable pulsed laser, and I said to him, 
"If you want to get the interest of physicists, then you should 
work on the hydrogen atom." That's about all I did on it, but 
he then made a discharge tubeyou could flow water through it 
and have a discharge which would produce hydrogen atoms, and 
observe the fine details of the hydrogen spectrum. That was a 
little later. I guess that was '71, probably after I came back 
from my sabbatical. 

Riess: This work shed new light in some basic areas? Is that what you 
mean about getting the interest of physicists? 

Schawlow: Well, yes, the theory of hydrogen atom the details are based 
on the theory of quantum electrodynamics which includes 
detailed interaction of the atom with the electromagnetic 
field. That theory is a very good one. Now Hansch has gone 
on, and others have too, to make really precise measurements on 
the hydrogen atom, and so far quantum electrodynamics is still 
okay. They haven't found anything wrong with it. 


Schawlow: From these first experiments he was able to measure the 

wavelength of the hydrogen atom line by a factor of ten or so, 
more precisely than could have been done before. The hydrogen 
atom line is very broad ordinarily, broadened by the Doppler 
motion. Hydrogen is a very light atom, so the atoms are moving 
rather fast, and that made the spectral lines kind of broad. 



And they knew from radio frequency experiments what hidden 
structure lies within this broad line, they don't know the 
relative intensity components. To find the center of the line 
of the components was hard, but he was able to resolve it very 
completely and could make a more accurate measurements of the 
absolute wavelength. He has gone on far beyond that in his 
work in Germany. 1 

I think one of the reasons he left us was thathe wanted 
to continue to refine these measurements on hydrogen, and it 
was just so expensive that we simply could not get enough money 
for it from American sources. I gather we had one of the 
largest grants in the atomic field, but grants in atomic 
physics are generally not anywhere near as big as in nuclear 
physics. We really couldn't afford to do the things they've 
been able to do in Germany. 

How long did he stay here? 

He stayed with us about fifteen years. We made him an 
associate professor after two years of post-doc--he wasn't 
willing to take assistant professorand then about a year or 
so later we had to give him tenure because other places like 
Harvard and Yale were trying to get him. He became a full 
professor quite young, because he was so in demand. We kept 
fighting off German offers, but eventually we couldn't. There 
were several things : Germany is home although his English is 
wonderful, he had a talent for languages as well as everything 
and it was only every couple of years that I might find a 
slight error in idioms or something like that. But they speak 
German in Germany, and they also have very good facilities. 

Doppler-free Spectroscopy 

Riess: And for your work it made a long-term difference to have Ted 
Hansch there? 

Schawlow: Oh yes. Yes. We switched directions entirely. We pretty much 
stopped working on solids and could do studies on gases. 

Ted had found a way to get rid of the Doppler broadening by 
using two beams going in opposite directions from the same 
laser, separated by a beam splitter. The only atoms that would 

'Ted Hansch is now a professor at the University of Munich and 
director of the Max Planck Institute for Quantum Optics. 



interact with both of those would be atoms that were standing 
still, because otherwise they'd be Doppler-shifted differently 
for the two beams. 

He applied that first to iodine vapor because he could use 
a krypton laser that we had bought. Iodine has lots of lines 
at all wavelengths so it was easy to get detailed spectra. 
Marc Levenson was a student who worked with him on that and he 
was maybe the best physicist I had of all my students. He did 
a very good job on that and then several other things, too. 

So he had this method of Doppler-free spectroscopy which he 
then applied to the hydrogen with a pulsed dye laser. The 
argon or krypton lasers wouldn't tune very far, just within the 
width of the line. But as I say, well, the old saying: "If you 
can't get the mountain to come to Mohammed, well, take Mohammed 
to the mountain." [laughs] If you can't tune the laser to the 
line, well you get something that has lines everywhere. 

That began to get me a little interested in molecular 
spectroscopy. For years I'd been telling people that a 
diatomic molecule is defined as a molecule with one atom too 
many [laughter] --if you get the second atom then things get 
much more complicated. You have vibration and rotation. Then 
I started thinking of ways you could selectively label a 
particular state, by saturating it. We began to do that and we 
found several different ways of doing that, using lasers to 
label states of molecules. 


Label them, yes. 

What we do is use one laser tuned to just one line in the 
spectrum and you chop this laser off and on. When it's on, it 
would saturate this line; that is, it would pump atoms out of 
the lower state so that there are fewer there, and all the 
absorption lines coming from that particular lower level would 
be weakened. So if you scan through it, you'd see those lines 
being modulated. They'd be alternately weakened and restored. 
Or you couldlater on, we used pulsed lasers and did a two- 
step excitation. The first laser would put atoms into an upper 
level and then a second laser would go on up from there. So 
again, you'd have labelled this one particular level. 

We were able to simplify a lot of spectra. We worked 
mostly on the sodium two, Na 2 molecule, which was complicated 
enough. Sodium is easy to vaporize, and it came at a 
reasonable wavelength for lasers in the visible, the yellow to 
orange red section of the visible. So we found a lot of new 


levels that hadn't been recognized before. And although I 
really wasn't too interested in molecular spectra as such, I 
was interested in this technique of simplifying spectra. 

Riess: What is the appeal? The simplification in itself? 

Schawlow: Yes, it is. I'd always thought molecular spectra were just too 
horribly complicated for anybody, although people somehow did 
analyze them. The thought of making them more tractable, 
although the procedure is tedious, still, it was powerful and 
that was an appeal for me. So 1 had several students working 
on various aspects of that. 

Brillouin Scattering: Marc Levenson 

Schawlow: We did a little bit of work on the Brillouin scattering. When 
I had that equipment grant, I bought a krypton laser. It was a 
fairly expensive thing. The krypton laser appealed to me, if I 
was only going to buy one. It had a wide range of wavelengths. 
They could tune it to just a few lines here and there, but they 
pretty much covered the whole visible spectrum. 

So we got this thing and people started asking, "Well, what 
are you going to do with it?" I thought, "Well, maybe I can 
look at the light scattering in bromine," which is a pretty 
opaque liquid in the visible. But this laser had one line out 
at 7900 angstroms which is really in the near infrared. 

I asked Marc Levenson to do that and he did a great job. 
He not only stabilized the laser by putting a Fabry-Perot 
etalon in the thing, I think temperature controlled, so he made 
the laser quite narrow band, but then he built a scanning 
Fabry-Perot to scan the spectrum. He did get the Brillouin 
scattering. He could measure the velocity of sound at ultra 
sonic frequencies in the liquid. 

But he noticed the shape of the curves from the 
interferometer were not quite right. There was a broad 
background which should have dropped nearly to zero. It had a 
background in between the peaks. He suspected that there was 
something else going on, so he looked at the spectrum with one 
of our spectrometers and found that there was indeed a broad 
background going out several hundred angstroms. He realized 
that this was due to hindered rotation of the molecules--they 
were interfering with each other in the liquidand he 





published that about the same time as someone else discovered 
that too. But it was something quite unexpected. 

Levenson really was very good. He'd really think for 
himself. He did most of his thesis extending the work on 
iodine that Hansch and he had started, on the iodine vapor. He 
measured how the splittings in hyperfine structure depended on 
the what particular vibrational state you were looking at, and 
found that the states near dissociation had a different 
magnetic splitting. A lot of sophisticated sort of stuff, but 
interesting and really quite exploratory. 

Did any Nobel Prizes come out of this work? 

No, I don't think so, although my Nobel Prize was given for 
contributions to the development of laser spectroscopy, so 
maybe it was some of this stuff, or may be the hydrogen work 
with Hansch. They of course knew that I had played a part in 
the transition from maser to laser. 

Did Hansch come up for a Nobel Prize? 

He doesn't have one yet. One of the problems, of course, was 
that a lot of the stuff that he did was done with me, and there 
were a lot of other people working on laser spectroscopy too. 

R.R. Donnelley Co. Project in Switzerland 

Schawlow: In 1974, I was asked by people from the R.R. Donnelley Company 
to consult on a project they were starting with a Swiss laser 
company. The aim was to see if they could develop a system 
using a large, rapidly pulsed laser to drill the holes in the 
copper plating of cylinders for gravure printing. The work was 
carried out at the plant of LASAG in Thun, with the 
collaboration of the laser group at the University of Berne. 
They had previously developed an automated machine for laser 
drilling of the holes in ruby watch bearings. 

For this project, I visited the beautiful little town of 
Thun several times a year, along with several Donnelley 
representatives. Although rather far removed from my previous 
experience, the problems were fascinating and I learned a lot 
about laser machining. 

At first some promising results were achieved, but 
eventually the task proved too difficult for the available 
lasers. Also, the Swiss franc rose sharply against the 


American dollar, making the work too expensive to continue. 
Although the agreement called for transfer of any technology to 
the Donnelley Company, it became apparent that there was really 
nobody who could make use of it. The chairman, Charles W. 
Lake, realized this and decided that their basic technology 
needed to be strengthened. To do that, he formed a technical 
advisory committee to meet several times a year. I was asked 
to serve on it, along with some very good people including Tom 
Everhart who later became president of the California Institute 
of Technology. 

At the meetings, some of their people would talk about 
particular projects, and we would ask questions, some of which 
must have seemed dumb to the experts. Mr. Lake, a truly 
brilliant engineer and manager, rarely asked the committee for 
advice but rather listened and then made his decisions. I 
think the meetings of the committee helped to clarify the 
thinking of those who made the presentations. Also, it helped 
the company to recruit some excellent young engineers. By the 
time that the committee was disbanded by later management 
around the end of the 1980s, they had a considerably broader 
technical staff. 

Cooling With Laser Light and Other Good Ideas 

Schawlow: In late 1974, we had the idea that you could cool atoms by 
using laser light, cool them down to very, very low 
temperatures and therefore narrow the spectral lines. We wrote 
a short paper that was published in Optics Communication in 
1975. We didn't do anything experimentally because we were 
interested in hydrogen particularlythat has the widest lines 
because it's so light. There wasn't, and still isn't, really a 
suitable laser for cooling hydrogen. So we just published this 
note, and I didn't even think to mention it in my Nobel 
lecture, but it has become a rather important field of physics 
since then. 

Steven Chu, who's now my colleague at Stanford, did the 
first experiments. Well, Letokhov in Russia, and I think John 
Hall at the Joint Institute for Laboratory Astrophysics at 
Boulder, did experiments on one-dimensional cooling of beams. 
But Chu did what we'd been talking about, three-dimensional 
cooling. He added some clever things to that that I hadn't 
thought of. One wasapparently he didn't know about our paper 
until after he had finished his work. He had the idea 
independently . 

Rless: He was at Bell Labs then. 

Schawlow: Yes, he was and he's a very bright guy too. So he had the 

idea--. We had calculated how long it would take to cool an 
atom, say, of sodium, because they can only absorb one photon 
every 10" 8 seconds, which is a short time. Each time they would 
scatter a photon, they would only lose about one centimeter per 
second of velocity. And they start out with about three 
hundred thousand centimeters per second, the average thermal 
velocity. So it would take a while and they're moving fairly 
fast, so I thought you'd have to build an apparatus about a 
meter in every dimension to cool these things down. 

But he instead used an argon laser to vaporize a little 
pulse of sodium vapor from a solid surface, and then just let 
the faster atoms escape, and the slower ones that remained he 
could then cool down to the very low temperatures. He started 
this field of optical cooling, and also of trapping atoms, 
which has become a big thing. This is one thing where we each 
came to the same conclusion about the same time, so 1 try to 
make the point that Hansch really did come up with the idea of 
laser cooling independently. 

(Steve Chu did win a Nobel Prize in physics this year 
[1997], sharing it with two other very good physicists who had 
made important advances in laser cooling. As soon as 1 could, 
I congratulated him, even though I had to tell him that he had 
spoiled my perfect record of never succeeding in nominating 
anyone for that prize. Of course many others probably 
nominated him, too.) 

Riess: When Hansch came, did you expand? 

Schawlow: No, I didn't. But I gradually gave up space and funding to 

him, I really let him take over things more and more. I tended 
to do [my work] with equipment that he wasn't using anymore. I 
really gave him priority over everything. I'd kind of make do 
with things that I could scrounge. I didn't spend very much on 

Riess: Why did you behave that way? 

Schawlow: Well, he just was so good and I didn't really want to get in 
his way. 

I did some other things that were quite different. We did 
this work on the molecules which wasn't thrilling, but it was 
interesting. Later, the last few years before I retired, I 
thought, "Well, I'll do something--! 've done enough that if it 
doesn't pan out, then it doesn't really matter to me so much." 


I got some students to work on looking for very weak absorption 
lines in rare earth metals. Those things are almost opaque, but 
still, the rare earth ions act like they're almost independent 
from a number of studies, from neutron scattering and so on. 

I had some very good students, Mike Jones and Dave Shortt, 
and they built a spectrograph that was very, very sensitive and 
could detect very small absorptions. They never did find any 
in a pure metal, but they found some metallic compoundsthat 
behave metallically. We found lines even in one that was a 
superconductor. Neodymium cerium copper oxide. We were able 
to look at it both above and below the superconducting 
transition. It has a transition at thirty degrees Kelvin or 

The way it was being done, Jones and Shortt just used a 
bright lamp to produce the absorption spectra and that produced 
a lot of heating, for example in helium which is then boiling 
vigorously. That's why you couldn't be really sure of the 
exact temperature of the sample. We couldn't really do what I 
would 've liked to do, which was to go carefully through the 
transition temperatures --which you could have done if we'd 
gotten the lasers tuned to that, once we knew where the lines 
where. We couldn't use the laser to search for the lines 
because it would take forever to search for lines, like looking 
for a needle in a haystack. So we had to use a conventional 

Tower of Babel 

Riess: In the introduction to this book it says that tunable lasers 

were taken up by scientists who were both laser physicists and 
spectroscopists. Spectroscopy was a separate branch of 
physics? I don't understand at what point one elects to be A 
or B. 

Schawlow: They probably drift into it. Laser physicists would be working 
on lasers primarily, and a spectroscopist might use 
spectrographs as they all had done before. And there always 
have been some. Spectroscopy was the hot field in the 1920s, 
and then it was considered a backwater in the thirties, the 
forties. However when they had lasers, that gave them a 
powerful new tool and they could do a lot more in Spectroscopy. 

Riess: When we talk about astrophysics or physical chemistry or laser 
physics or theoretical physics, these are discrete specialties 
but they all have to be taught in a university? 


Schawlow: Some places have specialized courses in them. We didn't 

really. We just sort of thought if you signed up to work with 
a professor doing things in that field, then you have to read 
up on it, teach yourself, learn some of the techniques from his 
laboratory, and go on from there. But you do have a Tower of 
Babel effect that it is getting harder and harder to understand 
people in different branches of physics. 

Riess: All with their own journals. 

Schawlow: Yes, Physical Review used to be one journal, but now it has 
five sections I think. One of these is nuclear physics, 
another one is particle physics. I think there's even one on 
theoretical physics. Section A is atomic and general physics-- 
I don't know, I used to get the whole thing, but they'd stretch 
from a volume of about this big for a year to this big. And 
very expensive, too, and you just couldn't store it. 

Riess: Doesn't it mean that people get more out of touch with each 

Schawlow: Yes. The only thing that brings them together is the things 
like Science and Physical Review Letters which has short 
articles from the various branches of physics. But even there, 
I find I can't really understand much of the things that are 
out of my field. 

Riess: Do you use your computer as a way of keeping up with physics? 
In other words, do you get on to the web? 

Schawlow: No, not really. The library has Physics Abstracts for the last 
few years and it's sometimes useful to search there, especially 
if you know the name of a person. The particle physicists, 
which is a very narrow field because they only have a few big 
accelerators, and are all working on similar problems, they're 
really desperately anxious to get the last word on something, 
both the theorists and experimentalists, and they post 
preprints on the web and people eagerly examine them, but I 
have never wanted preprints. When I see the article I want to 
do it once and not have to see an abstract and then later wait 
to get the full article. 

Riess: Why are they so desperate? 

Schawlow: It's a matter of getting something, an idea, that they can 

elaborate and publish something before somebody else gets the 


More so than in other fields of physics. 


Schawlow: Yes. Very competitive. I think it's because the accelerator 

is so expensive, they can only have a few of them, so there are 
only a few problems being addressed at any one time, and a lot 
of theorists are chasing the same problems. 

Riess: The science writers who are following physicists around, is it 
particle physics that they tend to follow? 

Schawlow: Astrophysics seems to turn them on most, then particle physics. 
Not very often the optical physics. 

More on Laser Cooling 

Schawlow: One thing that has caught their attention in the last couple of 
years is that Carl Wieman, who is one of Ted Hansch's students 
--now at the University of Coloradohas carried this laser 
cooling to the point that he, with Eric Cornell, were able to 
cool atoms down to the low temperature and of sufficient 
density that they got what they call Bose-Einstein 
condensation. That started with laser cooling and I'm really 
not going through all the advances that other people made in 
extending laser cooling. 

I guess I didn't explain how laser cooling works. It's 
very simple. The way we visualized it was that if an atom is 
moving and you have laser beams coming from all directions, 
from the six principal directions, that if the atom is moving 
toward the laser beamthe laser beams are tuned slightly below 
the resonanceif it's moving toward the laser beam, the atom 
sees the beam has shifted up into resonance, Doppler- shifted. 
So it'll scatter light, and every time it scatters a photon, it 
loses about a centimeter per second. On the other hand, when 
it's running away from the beam that's coming behind it, it 
doesn't see it because that's shifted farther down out of 
resonance. So this is a way of cooling free atoms without ever 
touching or making them condense. 

But other people found that by using the internal modes of 
the atom, they can get cooling that goes much beyond what we 
had predicted. Then they can trap them as pioneered by Steve 
Chu. He used a magneto-optical trap. Then they use 
evaporative cooling, where they just lower the trap slightly 
and the faster atoms escape, leaving it cooled. That way, they 
get down to extremely low temperatures, micro-Kelvins, where 
Kelvins is one degree absolute. And that's where they were 
able to get this Bose-Einstein condensation. Very much more 
has been added to it than what we did, but we did start it. I 


think that's my second most important paper, although I didn't 
think of it. 

Riess: When was that? 

Schawlow: It would be 1975. I worked on writing the paper when I was on 
sabbatical in London, in '74. 

Riess: "Cooling of Gases by Laser Radiation"? 

Schawlow: Yes. Optics Communication. 

Riess: You have Ted Hansch as the first author. 

Schawlow: Yes. Courtesy. Well, actually, we could have done it either 

There was one case where we were discussing it a little 
bit you often go through a state of confusion before clarity 
emerges when you take on a new problem. It seems almost 
necessary. So we were sort of thinking, "Well, we could 
scatter light. Let's see, would you want the laser to be tuned 
above that? Or below?" We were a little confused. Overnight 
we both came to the same conclusion, to tune it below the line. 

When we told people about it, we got two different 
reactions. One was, "Can't possibly work" because you're 
putting in energy and you're heating the thing. That wasn't a 
good reason because the laser has very little entropy, it's a 
very pure kind of light, it doesn't have a lot of randomness to 

Other people said, "Oh yes, it's obvious." [laughs] When 
some people said it's wrong and others said it's obvious we 
knew we had something pretty good. 

Riess: I should think people would be very reluctant to say something 
can't work. 

Schawlow: Oh, you'd be surprised. I remember people saying lasers 

weren't going to work, and they gave good reasons which are 
best forgotten. 

Charlie Townes, of course, tells about how Rabi and Kusch 
tried to argue him out of the maser. 

Riess: Did you and Ted Hansch do any work on that in the lab? 

Schawlow: No, no. We didn't even try to build or do laser cooling just 
wrote this theoretical paper and left it at that, because we 


really wanted to cool hydrogen and we couldn't do that because 
we didn't have a suitable laser for cooling it. So we just 
threw it out and let people see it. Run it up the flagpole and 
see who salutes, as they used to say on Madison Avenue. 


[Interview 8: November 26, 1996] i 

General Look at How Schawlow Works 

Riess: When you were working on a problem, let's say when you were at 
Stanford, who did you bounce your ideas off? I mean, is that a 
process for you? 

Schawlow: I had various students and postdocs and I guess I talked with 
all of them. We discussed things informally. 

Riess: Would you use Charlie [Charles Townes], wherever he was? 

Schawlow: No, I wouldn't use Charlie at all. No, he was doing different 
things, he was into astronomy then. And I really wanted to do 
my own thing, however insignificant that might be. 

Riess: And maybe the case is that one doesn't need to. 

Schawlow: Well, I was forty by the time I came here, I wasn't a kid 

anymore, I really was old enough that I should be standing up 
on my own feet. 

Riess: I'm not implying that. I'm wondering about the intellectual 
process, whether it's an internal thing--"This could work," 
"But no, that won't work." Does it all go on in the head? 

Schawlow: Yes, pretty much. But I did talk with students and I gave them 
a lot of freedom. I would sort of say, "This kind of looks 
interesting. Why don't you look into it?" And if they were 
good, they would find something that everybody hadn't thought 
about. But I would have pretty good instincts of things they 
could try. 



Some of them were also fiercely independent, like John 
Emmett particularly. But mostly they would go in the direction 
I had pointed them. I was just interested in exploring a lot 
of different things, so different students I would discuss 
different things with. We would have our group meetings every 
week. They would be pretty informal and I'd try and get people 

When you went to international meetings, was that a very 
fertile time? 

Schawlow: No, not really. It was sort of a waste of time. I guess I 

don't absorb things very well. I enjoyed going to them, but I 
don't really remember ever learning anything very clever. 

[laughs] I remember the first international meeting I went 
to back in 1955 when I was working on superconductivity. The 
thing that intrigued me most was to find out about something 
called Dexion, which is a kind of oversized Meccano erector 
set. Well, people at Bell Labs were already using that, but I 
hadn't known it. Everybody at these meetings wants to tell you 
what he's doing. 

We did have visitors who came by [Stanford], quite a few of 
them. It was a place that was sort of on the path when anybody 
came to the United States. It didn't seem to matter what part 
of the United States they were supposed to be visiting, they 
would somehow stop by Stanford. So we saw a lot of people, but 
I really don't think that they influenced me very much. I may 
have picked up little bits and pieces. 

I don't think these ideas we had were very wonderful 
anyway, but they were all something new and that was my main 
purpose, to do things that were new and not worry too much 
about how important they were. 

Riess: I need to be reminded that because you're a physicist does not 
mean you have a passion for every single aspect of physics. 

Schawlow: Oh, physics is much too big. I mean, really the old Tower of 
Babel effect is certainly working there. 

When I started out when I was a graduate student, I was 
interested in nuclear physics. I read pretty much what was 
available, and understood it pretty much, but, boy, that's 
gotten far beyond me. And particle physics I'd never gotten 
into. Even now in laser physics there are so many branches and 
so much elaborate theory that I've never been able to get into. 
It's discouraging. 


Riess: Do you think that people have unrealistic expectations of 
physicists as problem solvers? 

Schawlow: Well, we certainly have lots of problems to solve. 

I guess when I look back I sort of regret that I didn't 
find the big problems in science, and do something about them. 
I just did what I could, whatever lay at hand. As long as it 
was something that hadn't been done before I was willing to 
explore it- -even though I don't think anything I did really was 
of basic, fundamental importance like discovering quantum 
mechanics, relativity, or something like that, it wasn't in 
that league. 

Still, there were a lot of interesting things we turned up, 
and some of them provided a lot of work for other people to do 
afterwards, to clean up. 

Riess: If you say you regret that you didn't work on the big problems, 
do you have a hindsight about what those big problems were? 

Schawlow: No. Really, I don't think I could have done anything but what 
I did, really. I didn't have the instinct, or the theoretical 
knowledge. Indeed, of course, by that time the big excitement 
in physics was going into particle physics. That was something 
that you had to devote your entire self to, become part of a 
big team working on a huge project. 

When I came here I knew that SLAG was going to be built, 
and I hoped that somehow there 'd be some way of getting 
involved with it. But it clearly wasn't possible, so I didn't 
really try. Anything they did was done to a deadline. You 
would get time for a run on one of the big machines, and you 
had to get everything ready for that. And of course there was 
the earlier stage where you had to go and persuade them that 
your project was worthy of time on the big machines. 

It was a very competitive business and I really wasn't 
prepared for that. I didn't know the background or anything 
like that. It was really too formal for me. 

Riess: Earlier you mentioned that you organized public seminars at 
Stanford which allowed people to come in from industry and 
other campus departments . I ' d be interested in hearing all 
about that idea. 

Schawlow: Well, it was when I first came in 1961. For a year or two I 

ran these seminars and then I guess other people took over the 
idea. It was a time, you know, when nobody knew anything much 
about lasers and there was a lot of excitement. So we had 


people--! remember once we got Ted Maiman to come. Of course 
he had built the first ruby laser. He gave a good talk. 

And there were people in the engineering department who 
were interested. There was Tony Siegman and his student Steve 
Harris. Tony was a professor already and he had been working 
on microwave masers, and then started working on lasers, and he 
had some students. I guess Harris came along later, and Bob 
Byer, who was Harris' student, was later still. They are both 
on the faculty, have been for years and years now. We're 
talking a long time ago. When was this? Thirty- five years 

I don't remember exactly how long I kept it up, but I think 
it gradually became a more departmental sort of thing, and some 
of the individual groups were strong enough to have their own 
seminars. There is still such a thing going on under the 
applied physics department. Once a week they have a seminar 
which is advertised both inside and outside the university, and 
I guess some people come to it from other places. That's aimed 
a little more toward laser engineering than I'm able to 
contribute to. 

Riess: When you say outside the university, it's not that it's geared 
down to the public, but it's geared to industry. 

Schawlow: People in industry. There were companies starting up. Like 
Spectra-Physics started up to make lasers and was quite 
successful at it. Varian had some interest, and Lockheed too. 
I don't remember just what companies were involved. A lot of 
small companiesWatkins-Johnson did a little work on lasers 
and optics technologya number of other companies, some of 
which have disappeared. Anybody who was interested could come. 

Riess: It sounds like an important thing to get going. 

Schawlow: Burt McMurtry, I remember, was one of Siegman' s students. He 
did a clever experiment. He wanted to detect microwave 
modulation on lasers, and he wanted a fast-responding photo 
tube. He realized that he could take a travelling wave tube, 
which was intended to amplify microwaves, and if he just shined 
the laser on the cathode of that tube it would amplify whatever 
pulses were on the laser. So he didn't have to build a tube. 
He took a travelling wave tube and shone a laser on the 

He's done very well. He went and worked for a while at 
Sylvania, but then he got into venture capital and has done 
very well at that. 


Riess: I think of putting together that seminar as a way of thinking 
larger, and that's my question here. How do you broaden your 

Schawlow: I always read a lot of journals. I would subscribe to a number 
of journals--! didn't really have time to go to the library so 
I would get a lot of journals. For a while I'd keep them, but 
after a while I couldn't keep them. But I would skim through 
them every day as more would come in, and catalogs too, looking 
for ideas of equipment. 

I went to the meetings. The Optical Society would have 
one. And then eventually the Quantum Electronics Conferences 
would have exhibits. You'd see some new apparatus and get some 
ideas of things that you might use. And I'm sure I did pick up 
some ideas there. 

Prize-winning Work--Rydberg Constant 

Riess: Three of your accomplishments are listed in the book on the 

Nobel Prize winners in physics: the observation of the complete 
hyperfine structure of a molecular iodine line; the first 
optical measurement of the Lamb shift in atomic hydrogen; and 
the most precise measurement of the Rydberg constant in 
hydrogen. ' 

Schawlow: I have to admit that Hansch really did most of those things. I 
encouraged him and provided equipment for him, but the iodine 
thing was really done while I was away. I had, however, bought 
a krypton laser thinking that it would be useful for something 
or other. So it was there. I had Marc Levenson working with 
it to make it very monochromatic for some Brillouin scattering 

Hansch did have the idea of getting rid of the Doppler 
broadening from the thermal motion by sending two beams in 
opposite directions through the cell containing the gas. Then 
he would chop one beam and then look at the other beam to see 
if it was modulated. If the beams were tuned either below or 
above the center of the absorption line, they wouldn't interact 
because they'd be seeing atoms going in different directions 
because of the Doppler shift. 

l Nobel Prize Winners, Physics, edited by Frank N. Magill, Salem Prize, 
Pasadena, 1989. 


However, when they're tuned just to those atoms that were 
not moving at all, or perhaps moving a little sideways, they 
could interact with the same atoms , and the one beam that was 
chopped would saturate those atoms and decrease their 
absorption and so let more of the probe beam through, so it 
would modulate the probe beam. This was a very clever idea 
that Ha'nsch had. 

Also a similar idea, about the same time, from Christian 
Borde--it actually has roots in the things that had already 
been done in spectroscopy of laser gases, where they'd noticed 
the dip when they were tuned to the center of a line. Because 
there they have two beams going- -this is for the gas inside the 
laserthey do have the two beams going in opposite directions. 
But what Ha'nsch introduced was using two beams externally and 
chopping one of them so that you could sense or detect the 

Well, he had this thing, and he also had found a way to 
tune the pulsed lasers so that they were fairly monochromatic, 
a fairly narrow band. You could tune those anywhere in the 
visible. So I said, "Look, if you want people in physics to 
pay any attention to you, you should look at hydrogen." That's 
the one that people really think they understand, it's the 
simplest atom. 

So he went to work and he did it, built a gas discharge 
chamber for producing atomic hydrogen and passed the two beams 
through that, and was able to resolve the fine structure in the 
hydrogen spectrum. 

Well, at first he did that, we thought, "Maybe that'll 
permit us to measure the splitting." But it turned out that 
they were already well-measured from microwave studies, so what 
was left was to measure the absolute frequency of the line. 
Certainly after your question before of "Who did I talk 
with?" well, certainly I talked a lot with Ha'nsch after he 
came and discussed ideas with him. 

So the thing you could do was measure the absolute 
wavelength. Now, even if you'd known where all these lines 
were under this Doppler-broadened spectrum, you couldn't really 
tell exactly where the center of the lines were because you 
didn't know the relative intensities of the components. So 
once they were resolved he could start measuring the absolute 
wavelength and therefore get a value for the Rydberg constant, 
which is one of the fundamental constants of physics. It 
measures the binding between electrons and nuclei in atoms. He 
did improve the accuracy of that by about a factor of ten or 


Since then, he's gone on, and others have too, and they 
have improved the accuracy by maybe a factor of a million or 
so. That's a complicated business. 

Quantum Electrodynamics 

Riess: What is that kind of accuracy good for? 

Schawlow: Only for basic physics, I think. Well, a hydrogen atom is 
something they think they can understand quite completely 
through quantum electric thermodynamics . Indeed they can 
calculate the energy levels with great precision in the 
splitting, in the Lamb shift and so. So one needs to verify 
that to see whether that really is exact. It's a test of 
quantum mechanics. So far it's passed every test. 

The calculations have become extremely complex. They have 
to use more [Richard] Feynman diagrams than the ancient 
astronomers used epicycles. But there's a systematic procedure 
for doing these Feynman diagrams. Although it requires big 
computers and a lot of patience, still some theorists do go on 
calculating them, and so far they agree very well. In the 
latest measurements they can see an effect due to the size of 
the nucleus, which could be ignored in the earlier work because 
the nucleus is much smaller than the electron's orbit. 

So far they haven't found anything wrong with quantum 
electrodynamics, which in a way is a little disappointing 
because you'd hope to discover something new and exciting. But 
it's essential to test these theories as well as you can, and 
they can test them much, much better than was ever believed 
possible in earlier years. 

Riess: The search for something wrong opens another avenue. 

Schawlow: That's the way physics goes, really. A lot of the time you 

hope something will not work. You have Michelson's experiment 
on the ether drift and it turns out there wasn't any. Then 
Lamb and [J.R.] Retherford in 1947 or so detected a Lamb shift 
between two levels in the hydrogen atom that were thought to 
have exactly the same energy, the 2S and 2P levels. 

There 'd been some hints of that before, even some 
measurements that had indicated it, but others had disagreed, 
so it was not clear until Lamb and Retherford used a radio 
frequency method that didn't have to worry about the Doppler 
broadening of the spectral lines. And of course that's what 




Lamb got his Nobel Prize for. It was one of the things that 
inspired [Shinichiro] Tomonaga and Feynman and [Julian] 
Schwinger to develop quantum electrodynamics , for which they 
got their Nobel Prize. 

Those quantum electrodynamic calculations have been refined 
very much. Interestingly enough, Paul Dirac, who developed the 
relativistic theory of quantum mechanics in 1928 or something 
like that, never liked quantum electrodynamics. I heard him 
talk about it at one of the Lindau meetings of the Nobel Prize 
winners, in 1982. 

I happened to have a tape recorder with me at that meeting 
and I taped Dirac 's talk and gave a copy to my friend George 
[W. ] Series--! transcribed it and he got permission to publish 
it in the European Journal of Physics. Essentially Dirac said 
that quantum electrodynamics is not a real theory, it's just a 
prescription for calculating, but it's an awfully good 
prescription for calculating. [laughing] 

One keeps hoping there will be some much simpler way of 
looking at what should be a simple thing with just one electron 
and one nucleus. But they have to take into account the 
interaction with the radiation field, polarization of the 
vacuumit becomes extremely complicated to try to do exactly, 
but apparently they can, and so far neither that nor other 
precision experiments, like the ones that Dehmelt got his Nobel 
Prize for, have shown anything wrong with quantum 
electrodynamics . 

They keep on pushing, and I'm sure that Hansch and others 
will get another factor of ten or so and send the theorists 
back to their pencils and their computers. 

Would you characterize this as the search for the secrets of 
the universe? 

Yes, it is part of that, yes. It's part of the search for the 
laws that govern the universe. You test the ones you know and 
see if anything 's wrong. If so, then you may have to get a 
totally different approach that looks quite different but 
somehow includes all the old results. An example of that, of 
course, is relativity reduces to Newtonian mechanics if the 
speed is not close to the speed of light. If it's much less 
than the speed of light, then Newtonian mechanics is very good, 
yet it looks quite different when you do relativity. 

One hopes that maybe there ' 11 be some new way of looking at 
things that'll make things simpler. But making them look 
simpler is not enough, they have to predict all the old 


results, and now there are very many good results of quantum 
mechanics, and also some predict some new ones that differ from 
quantum mechanics. That's still an important search, but it 
takes a certain amount of courage to say that that's what 
you're going to do. 

On the other hand, you can go ahead and measure some things 
which might possibly throw some light on it. But one has a 
feeling sometimes that it's sort of like the drunk who is 
looking for his lost quarter under the lamppost, "because 
that's where there's light" [laughter] you didn't necessarily 
expect it there. 

These things where we've made discoveries beforepeople, 
for instance, have tried the Michelson Morley experiment using 
lasers and increased the accuracy by many orders of magnitude, 
but the results are still the same. And so it is with quantum 
mechanics. Perhaps if a surprise is found it won't be found 
there, I mean, in doing the old experiments with better 
accuracy. But you don't know. So you do what you can. 

Riess: Do you have some thoughts on the work of Stephen Hawking? 
he fit in anywhere here? 


Schawlow: I've never had any interaction with him, I've never met him. 
He's a theorist, and he does interact with a number of other 
theorists. They have discussions and arguments, probably. But 
basically in the end I guess it's his own ideas that he writes 

Riess: He has quite a public following, like Feynman had. 

Schawlow: Yes, he's well known because he writes so well and because he's 
so handicapped. But there are others in cosmology, quite a few 
of them whowell, they publish obscure papers that are hard to 
read. They don't always agree with Hawking, and sometimes 
they're right, sometimes he is, or sometimes one doesn't know. 

Scientific American published a debate between Hawking and 
Penrose a year or so ago about some aspects of cosmology. I 
wasn't really interested enough to try and decipher it very 
thoroughly. I think a lot of it is speculative. 


Schawlow: I know Hawking "s work only secondhand through popular accounts, 
but I believe he did show that black holes could radiate away 
some energy because of quantum effects, quantum mechanical 
effects, which hadn't been thought about before. Otherwise, 


black holes --any thing that fell into them was going to stay 
there forever and had no way of getting out. 

I think he has convinced people that there are quantum 
effects, that they do radiate something or other. Of course, 
there's a lot of radiation from the region around the black 
hole, a lot of material that's drawn into it and accelerates as 
it's going in. But it's a different frontier of physics. 

And then of there are the particle physicists who feel that 
they have the frontier. That if only they can get some bigger 
machines they may find the Higgs boson which can explain why 
all the other particles have mass. Of course I don't know who 
explains why the Higgs boson has mass, but I don't understand 
that that well. 

Riess: What you're doing is lining up a list of what we would call the 
sexy questions in physics. 

Schawlow: Yes, yes. And I've never really worked on them, I sort of poke 
around the corners and see what I can find. 

Riess: And yet the laser, at a certain point, was the sexy discovery. 

Schawlow: Yes it was pretty sexy for a while, at least among the 

engineers. It also attracted a lot of theorists who wrote 
elaborate papers which I couldn't understand. 

First of all, we thought of it in the semi-classical way, 
thinking of the light wave as being a classical wave to 
interact with quantum mechanical atoms and use the quantum 
mechanical process of stimulated emission. But this didn't 
satisfy people like Willis Lamb who wanted to quantize the 
field too. And you can do it, but it gets a lot more 

I think it was in connection with that work that he 
proposed what's now known as the Lamb dip- -not the sheep dip, 
the Lamb dip [laughter] --where if you tune gas lasers like 
helium-neon exactly onto the center of a line, then the output 
drops. That's because the two waves from the opposite 
directions are drawing on the same supply of atoms. This was 
certainly a predecessor of Hansch's Doppler-free saturated 
absorption experiment. 

Now, let's see, there was a third one that you mentioned. 

Hyperfine Structure of Iodine 

Riess: We talked about the Rydberg constant, the Lamb shift, and the 
first was the hyperfine structure of iodine. 

Schawlow: Iodine, right, yes. Well, I went with some of these things. I 
had Marc Levenson measure the hyperfine structure of all the 
lines that he could reach. This was a case where he was using 
a gas laser that did produce a number of different wavelengths, 
maybe a half a dozen or so in the visible, but it wasn't 
continuously tunable. However, the lines were quite narrow 
when you could tune them. 

So Levenson looked at those lines of iodine that he could 
reach and he studied the systematics of how did the hyperfine 
splittings change. There 'd been some theorists who had 
suggested that the quadropole splitting, which is caused by the 
shape of the nucleusnot being spherical, they're sort of 
football- shaped- -would change markedly as you got up toward the 
dissociation energy of the molecule, which he could approach. 
That didn't happen, so that was something he found. 

Then there was a magnetic splitting also. That did get 
large as he got close to the dissociation, which he interpreted 
as a mixing in of another state that was near the dissociation 
level that had a different magnetic property. When they get 
close together they mix in a little bit of the properties of 
that other one. So we followed up on that. 

His Ph.D. oral came just after Linus Pauling had come to 
Stanford. Pauling wanted to see what was going on in physics, 
so he volunteered to preside at a Ph.D. oral and Levenson was 
the first one, which actually was not so far from things that 
Pauling had done in molecular theory. It certainly was an 
extension of them. Pauling was quite polite and friendly, but 
I'm sure that must have made Levenson a little bit nervous 
because he was the great expert on molecular theory at that 
time, or had been. 

Let's see, then I posed some alternative methods for really 
sensitive detection instead of using absorption. The trouble 
with iodine was that at the lowest pressure we could get by 
cooling it the lines were still pressure-broadened. That was 
not because we couldn't cool it more, but if we did there 'd be 
not enough vapor to see, there wouldn't be enough absorption to 
see the changes in the absorption. So I thought of using the 
fluorescence because when it is excited it fluoresces. And we 
were able to go down a number of orders of magnitude. 


About that time, I guess, continuous wave dye lasers were 
beginning to come in, and Bill Fairbank, Jr., who was the son 
of one of my colleagues, was working for me, and I suggested 
that he build a continuous wave dye laser. Well, the gain of 
the dye lasers, the continuous wave one, was not very high, and 
you couldn't put tuning elements in it the way you could in the 
pulsed dye lasers, where you had a lot of gain. So this thing 
was rather a Rluge . 

Riess: Rather a Kluge? 

Schawlow: Kluge--K-l-u-g-e. Haven't you ever heard of Kluge? 

It was a complicated thing with external tuning elements 
outside of a laser cavity, and it was difficult to tune. But 
you could tune it to the sodium resonance, one of the bright 
yellow D-lines, and then use this fluorescence to get a 
relative measure of how much was there. He was able to cool it 
down to below zero Celsius, I think minus twenty or something 
like that, and measure the vapor pressure of the sodium at 
about a factor of a million lower than it had ever been 
measured beforeas it went down in temperature. 

So this was a very sensitive methodin fact, we realized 
that at the lowest temperatures there probably was only one 
atom at a time in the beam, that you'd accumulate light for 
some time. In fact, at those temperatures the mean-free path 
between collisions was greater than from here to the moon. 

Riess: The mean free path? 

Schawlow: Between collisions of sodium. There were so few sodium atoms 
that they just wouldn't ever collide. They'd collide with the 
walls of course, but not with each other. 

Riess: Well, that's a very neat experiment. 

Schawlow: Yes, I thought that was kind of cute. He built this thing, and 
it really wasn't good for much, so I sort of pulled the rabbit 
out of the hat by suggesting he measure the vapor density. And 
he did it. Of course I didn't do it. 

Riess: Your responsibility in giving ideas to people just starting 
their careers--it can be a make or break thing, can't it? 

Schawlow: Yes, I think so. And sometimes I would find students just 
couldn't do things the way I suggested and I'd have to give 
them something simpler, or get a new student to come in and 
help them. 


Students work in different ways. Most of them are much 
stronger in formal theory than I was. I think I annoyed some 
of them because I'd do more hand waving because I was trying to 
understand the basic processes rather than the details of the 

The Apostolic Succession Phenomenon 

Riess: In the process of putting a student together with an idea, do 
you have to have a grip on the student ' s psychology or his 
whole modus? 

Schawlow: Well, you try. Sometimes you'd guess, and you wouldn't always 
succeed, as I say. Sometimes they couldn't work that way. 

I had one student who just could not work by himself. He 
started out--as I often did, I'd have a beginning student work 
with an older one. I used to call it Apostolic succession, 
[chuckles] So John Holzrichter worked with John Emmett, and 
Holzrichter was a brilliant experimenter and has gone on to do 
nice things at Livermore. He was in charge of building their 
first big laser before fusion, and now he's in charge of their 
independent research- -they have a certain amount of freedom to 
do things on their own. 

When he was finishing up, I had Jeff Paisner start out to 
work with him. Holzrichter and Paisner did very nice things 
together, and I thought Paisner could just go on and do a bit 
more of the same. But nothing happened at all. 

And then Serge Haroche came from Paris, a very brilliant 
guy, a wonderful person, and still a very good friend. Serge 
Haroche is now the head of the physics department at the Ecole 
Normal in Paris, which is one of the Grandes Ecoles, a very 
distinguished position. He had a bright idea of looking for 
what's now known as quantum beats, where you put a pulse of 
laser light on sodium vapor, tuned to the absorption line. But 
it would be a short pulse and the spectrum was broad enough so 
that it would excite several hyperfine components, sort of in 
phase. Then the thing afterwards would radiatewell, it was 
sort of like he lined up the atoms and then they precessed, 
like a searchlight that goes by you and you get alternations of 
lighter and darker. 

Well, I got Paisner working with him, and things were going 
great, and I'm sure that Paisner made a real contribution. 


Then Haroche left, and I said, "Well, you could do a little bit 
more here" and nothing happened. 

National Ignition Facility Work, and Military Sponsorship 

Schawlow: Finally Richard Wallenstein came from Germany and they did some 
nice work on quantum beats in molecules. He's a very good man, 
Jeff Paisner is, and he's done well at Livermore and published 
some nice work. He is now in charge of the design of the 
National Ignition Facility, which is going to be a super giant 
laser for fusion. 

Riess: I remember you mentioning that, and I was thrown by the name. 

Schawlow: It's a giant laser, or set of laser beams, that will be focused 
on a little pellet of heavy hydrogen. They will get enough 
energy so they hope that they get more out in the resultant 
explosion than they put in. The laser will heat it hot enough 
and compress it so that the heavy hydrogen combines to produce 
helium and release energy that way. 

Riess: For a practical energy source? 

Schawlow: They say that if you could tame it you could provide the 

world's needs for practically foreverthere' s enough heavy 
hydrogen in sea water. 

But in fact now the sponsorship is military because they 
want to simulate hydrogen bomb explosions, and they can do that 
and really make measurements on them that they couldn't make on 
bombs, particularly because they're afraid that there might be 
a treaty banning all nuclear tests, which is I think quite 
possible. Then they only way they could do research on trying 
to understand and improve the hydrogen bomb would be with this 

Riess: Tell me why understanding and improving the hydrogen bomb is an 
important way to go. 

Schawlow: Look, I don't understand the military mind, at all. 

However, it's certainly possible that if they could tame 
the thing- -the trouble is that as the work has gone on the 
threshold has gotten higher and higher, so that they will have 
to put in something more than a million joules in one pulse. 
And the output will be something more than that, so it's a very 



big explosion that they'll have to contain to convert it into 
usable energy. 

They have some schemes, including having the thing in a 
cell whose walls are coated with liquid lithium that would 
absorb the neutrons from the blast and convert that into heat 
and then electrical power. But these things are still untried, 
and it isn't easy. 

As I've said, it reminds me of the story of the king in the 
olden days who wanted to have some oak trees in front of the 
palace and told his prime minister, "Get a hundred men tomorrow 
and have them start planting a thousand oak trees in front of 
the palace." The prime minister says, "But Sire, why the 
hurry? Those oak trees won't be fully grown for a hundred 
years." The king said, "A hundred years? Have them start 
today." [laughter) 

The possible payoff is enormous if you could tame nuclear 
fusion. Of course, this competes with the gaseous discharge 
work on nuclear fusion, the sort of thing that's been going on 
at Princeton. They both have difficulties. 

If the military will pay, that's the way to get it paid for. 

Well, it is, but I think the military really want that 
information. They want to know everything about hydrogen 
explosions, thermonuclear explosions. 

Work and Publications with Students 

Riess: I'd like to talk more about your students. You've already 
talked about many of them in the process. The first two 
graduate students to join the Schawlow group in 1961 were 
George Francis Imbusch and Linn Mollenauer, and you've talked 
about them. 

Schawlow: We had a lot of fun together with Imbusch and Mollenauer. I 
think I've said before, Imbusch was very quick at getting 
things done. 

Mollenauer was not quite so quick but he was a deep 
thinker and usually came up with something I hadn't thought 
about. He's done very well. He's been at Bell Labs for many 
years and he really was one of the first to show that optical 
solitons, solitary waves, could exist in glass fibers and that 
they would be a very good way to transmit information at high 


speed because these things retain their shape, even if there's 
attenuation. And they can be replenished; if a signal gets 
weak, they can be reconstituted exactly the same as they were. 

Riess: Perfect for Bell Labs. 

Schawlow: Yes. Well, they haven't decided to put that system into work 
because this is a huge investment in these fibers, but still 
there and at other laboratories around the world it's being 
extensively investigated and looks like a real possibility for 
the very high speed communications. 

Imbusch, despite his German- sounding name- -I think his 
family came from Austria originally- -his father was Irish and 
was a cabinet maker in Limerick. Imbusch went to University of 
Galway, where he could get a free education if he'd do it in 
Gaelic, in the Irish language. After finishing his Ph.D. he 
spent a couple years at Bell Labs, and they would have very 
much liked to keep him, but he went back to Ireland and has 
been a professor at Galway, and has continued to work on the 
spectra of ions and solids, and energy transfer among different 
ions. I think he's been a dean; he's certainly been an 
important official in the University, and in Irish physics in 

Riess: Did Bell Labs ever underwrite work out here? 

Schawlow: Well, they certainly never underwrote anything for me. I know 
when I was there, there was a feeling that, "Well, we're 
supporting science by providing new results from our own 
laboratories." They had given grants and fellowships, but I 
never had any direct contact with that. They never seemed very 
interested in what I was doing. As I say, I was going my own 
way, trying to stay out of the way of the thundering herd. I 
didn't want to get trampled on. 

Riess: A student named Warren Moos "joined the fledgling laser 
spectroscopy group in 1961." 

Schawlow: He was a postdoc who came from Michigan and he was interested 
in photochemistry and several other things . He actually had a 
student in engineering, Richard Soref, work for him on 
nonlinear optics. 

Moos went to Johns Hopkins and became an assistant 
professor and has been a professor for many years. He switched 
to rocket astrophysics, where they send up rockets above the 
atmosphere and can photograph things in the ultraviolet and 
infrared, although only for a relatively brief period. I think 
he's done well at that, but I haven't followed him in detail. 


Riess: Now, when we're talking about students, these are really 
graduate students. These are not postdocs. 

Schawlow: No, I didn't have very many postdocs. Bill Yen was one, Moos 
was another. 

Riess: Bill Yen came in 1962. 

Schawlow: Yes. There were two students from Washington University that 
were somehow being pushed for postdoctoral jobs. One of them 
was Yen, the other one was Schwettman, Allan Schwettman, and 
he's still here. He worked for Fairbank on the superconducting 
accelerator, and he still continues to work on that even though 
Fairbank is long gone. 

Riess: Did Bill Yen originally get his education in China? 

Schawlow: I think not. His father was in the diplomatic service, and he 
didn't live in China very long. He said when he was about 
fourteen or so, he had to go back to China, to Shanghai. He 
grew up in Mexico City, mostly. His father was in the 
Nationalist diplomatic corps, and later was ambassador to 
Venezuela. I used to kid Yen about being the only person who 
spoke Chinese with a Mexican accent. He took some high school 
work in Shanghai. He said that was rough because he really had 
a lot of Chinese to learn and it's a difficult language. 

But he came back to the United States and went to the 
University of Redlands I think, in California, and then to 
Washington University at St. Louis, where he worked on nuclear 

Riess: And he was in the initial group with Imbusch and Mollenauer? 
Schawlow: And Moos, yes. 

Imbusch, I think, worked mostly on magnesium oxide, with 
chromium in it, which is another crystal that's a little 
different from the sapphire because the chromium ion is really 
in a site of cubic symmetry. Although chromium has a charge 
three, and the magnesium that replaces it has charge two, so 
there has to be some charge compensation somewhere else in the 

Do you have the bibliography that I give you, the 
publication list? It might help me remember who did what. 

[Riess passes bibliography to Schawlow] 


Schawlow: Yes, here. We collaborated a little bit on energy levels in 
concentrated ruby with Paul Kisliuk and Mike Sturge at Bell 
Labs--Mike had come from England and had taken over my big 
spectrograph at Bell Labs. We studied temperature dependence 
of the width and position on the strong red lines in chromium 
and vanadium in magnesium oxide, again with some collaboration 
from Sturge at Bell Labs, and [D.E.] McCumber, who's a 
theorist. [Number 62 in publication list.] 

Riess: This was in the early years? 

Schawlow: Yes, 1964. Then Yen and [W.C.] Scott, who was a student, 

worked on praseodymium in lanthanum fluoride. [Number 66 in 
publication list.] We got into that partly because I was 
consulting with Varian. They were somewhat interested in 
getting into more fundamental research and they hired a crystal 
grower who liked to grow lanthanum fluoride crystals and could 
put various ions in it. 


Riess: Let's continue to review work you did with this group. 

Schawlow: I probably shouldn't spend too much time on it, but you asked 
who some of these people were. Jake [J.Y.] Wong. "Far 
infrared spectra of V4+ and Co2+ single ions in corundum." 
[Number 78 in publication list.] 

There were so many different things we did. We were trying 
to understand the splittings of these satellite lines in ruby 
and we had at one time tried to identify two of these lines 
coming from the same kind of chromium ion pairs, in which case 
there should be a far-infrared line connecting these two levels 
that show the splitting. Well, we thought we would check that 
out, but we were beginning to doubt it after we studied the 
thing a little more carefully. Jake Wong was the chief man on 
that. Mike Berggren helped with that too. 

Then it was Ed Nelson who built a far infrared spectrograph 
for us. [Number 80 on publication list with E.D. Nelson and 
J.Y. Wong.) I got a huge rod of ruby, about six inches long, 
dark ruby, and about three-quarters of an inch in diameter. 
And there was no absorption at those wavelengths, but on the 
other hand we got a more moderate sized crystal of aluminum 
oxide containing some titanium and we saw the line . I told you 
that story earlier. [See p. 239] That was work with Nelson and 
Wong. Nelson built the spectrometer. 

Steve Johnson came in the late sixties, and he did some 
work on excited states in ruby and emerald. He's now at the 




University of Utah working on biomedical imaging. I had gotten 
him to try and build a novel kind of spectrograph. 
Photographic plates have low quantum efficiency, but they do 
take all the light all the time. I thought a television type 
pickup tube would do that even better because it's more 
sensitive and gets all the light all the time. 

Johnson worked for several years building such a 
spectrograph using an image orthocon, which was state of the 
art in those days but unfortunately not a great choice for this 
because it's kind of a finicky thing, not as stable as one 
would like for a spectrometer. Now, it's very common that 
people use what they call optical multichannel analyzers, which 
usually use an array of diodes to take all the light all the 
time and read it out in scans. 

Johnson was very stubborn. At one time we had some money 
left over and I wanted to buy a commercial tv camera setup and 
he wanted to build his own. He spent several years doing that, 
but he learned a lot about imaging, and so he's gone into 
biomedical imaging ever since. 

Another student I had was Stan [E.] Stokowski, who had done 
an undergraduate thesis with Charlie Townes at MIT, the only 
one who ' s ever worked for both of us . I had him doing some 
studies of line shifts of chromium in strontium titanate, which 
is a ferroelectric crystal. It's a crystal where the electric 
field moves the ions around rather easily so you get a large 
susceptibility. We actually were able to finally see a change 
in the intensity of the lines as well as the positions when you 
applied an electric field. [Number 91 in publication list.) 

Much of this sounds like chemistry to me . 

It was close. I was a member of the division of chemical 
physics of the American Physical Society. This sort of stuff 
was done in the Electrochemical Society too, although I never 
did get involved with that. 

Peter Toschek? 

He was just a visitor, a nice guy. Hansch worked with him for 
his Ph.D. thesis. He insisted he wasn't Toschek's student, 
Toschek was a postdoc there, but they both learned lasers 
together. Neither of them had done anything with lasers 

Larry [S.] Wall did work on stress-induced phase 
transitions in strontium titanate. [Number 101.] I had a lot 
of students. I had forty altogether. 


Chinese Physics Graduates 

Riess: You had a number of Chinese students. How was their 

orientation different from American students? Can you make any 

Schawlow: Wong had his undergraduate education in this country, at 
Princeton. He was from Hong Kong and certainly fluent in 

Riess: And Zugeng Wong? 

Schawlow: He was just a visitor [1982-1983], Wong Zugeng. 

I visited Shanghai in 1979. That was the first exchange 
where the Chinese Academy and the National Academy of Sciences 
agreed to exchange a certain number of lecturers. Each one 
would go to a different place and they'd bring students from 
all over China to hear the lectures. So I went to Shanghai 
Normal Universitylater it became East China Normal 

University. That was supposed to be a 
had considerable research going on. 

teacher's college but it 


There was a professor there named I-shan Cheng who had 
gotten a Ph.D. at Ohio State in molecular spectroscopy in the 
1940s. They weren't giving Ph.D.s at Chinese universities at 
that time. But they had a number of people doing research, 
generally under his direction, and he asked if we could have 
some of them come visit and work in our laboratory. They 
supplied the money for support for them so 1 didn't have to pay 
anything. So I said okay. 

And there was also Xia Hui-Rong. Xia is the family name, 
but she was the wife of Wong Zugeng. She was a good physicist, 
and she died just a few weeks ago in a bicycle accident on the 
campus of East China Normal University. She was here for a 
year, and then she was at the University of Colorado for 
another year, I think. Her husband, Wong Zugeng, was also a 
pretty good physicist. I think he became head of the physics 
department there. 

Anyway, she was in a bicycle accident. They don't wear 
helmets in China, and she somehow hit her head, was in a coma 
for a week, and died. 

Then there's Zhang Pei-Lin? 


Schawlow: Zhang Pei-Lin. He also was not a student, he was a visitor in 
1983. He was from the Institute of Physics in Beijing and he 
was quite a good man too. 

There was another Wong in there, Wong Zhao- Young, who was 
from Fudan University in Shanghai. He was only able to stay 
for nine months, so he didn't get as much done as the others 
did. He later became head of the physics department there, but 
then much to my surprise he moved to Hong Kong and became a 
member of the physics department at one of the universities, 
Baptist University, I believe. 

I hate to go on print saying that I just can't remember 
people. And I can't remember a lot of people. It's terrible 
at times. 

Riess: Can you make a generalization about the approach to physics of 
the Chinese, or the training? 

Schawlow: I think the general thing I felt when I visited China in '79, 
the first time, was that they were very capable and had built 
just about every kind of laser that had ever been in print, but 
they didn't have any idea what to do with them. They really 
didn't have very creative ideas. 

The people in Shanghai under Professor Cheng were trying to 
measure atmospheric pollution using two carbon dioxide lasers, 
one of which was tuned to an absorption line of a pollutant and 
the other was tuned off it . And that ' s a very good way to do 
it, and they were actually measuring some pollution from smoke 
stacks. But most of the other people I saw really didn't seem 
to have any very good ideas. I'm sure it's much better now. 

The other thing I found is that they were trained very 
narrowly. They wouldn't know anything at all about nuclear 
physicsif they were going into laser physics and optical 
physics that would be all they'd know. And they'd know that 
pretty well, what was in the books they would know. But they 
wouldn't know anything at all about other branches of physics. 

Riess: Did you feel that they looked to you as a leader more than 
other students might have, that the reason they didn't have 
ideas was because somebody else was always supposed to have 
ideas? Or they didn't know what they were looking for because 
somebody else usually told them? 

Schawlow: Well, this was when I visited China. The ones who came here, 
yes, they developed ideas as they went along. Again, I would 
kind of aim them in some direction and let them go, and then 
they thought of things, they developed ideas. 


Particularly Yan Guang-Yao. He came in that group in 1979. 
Professor Cheng, who had been very badly treated during the 
Cultural Revolution, I think sort of looked after Yan, who 
wasn't a Communist--! think the rest of them were and because 
of that he was sort of low man on the totem pole around the 
university. But Cheng particularly suggested that we take him, 
and he was really the best of the bunch as far as producing his 
own ideas, and carrying out experiments too, although the 
others were okay. 

In 1984 when I visited again I didn't have any postdocs and 
was sort of lookingit would be nice to have somebodyso I 
invited Yan to come back, and he came with his wife and son. 
Now he has no intention of moving back to China and he has his 
green card I don't think he's a citizen yet. He worked on his 
Ph.D. for quite a long time. 

He was here first just as a visitor. Then when we could we 
made him a graduate student, when he could do that without 
having to go back, and he worked there for quite a while. As 
soon as he could finish his Ph.D. without having to return he 
finished it. He'd written twenty papers by that time. Then 
well, he was close to fifty and his English accent was pretty 
bad so it would have been hard for him to find a teaching job, 
but a job opened up running the lecture hall demonstrations at 
Stanford and he took that on and is doing a good job there. 
It's not really a research job, but it does require some 
knowledge of physics and apparatus, which he supplies very 

Riess: The dead horse that I'm beatingthe world view of someone 

educated in China is not so different that they don't look at 
questions of physics in a very different way? 

Schawlow: I don't think so, no, not the people I knew. They seemed very 
normal . 

I think now, of course, laser physics in China, and 
spectroscopy, are doing some original things. They have some 
crystal growers who have developed some special crystals for 
harmonic generation and mixing of different wavelengths that 
are some of the best in the world, producing materials that are 
sold everywhere. 

I didn't have any students who were directly from mainland 
China. We did start admitting a few in the eighties. We had 
to keep the numbers down because we're not a very big 
department and we could easily have filled the place up with 
Chinese students. I think, though, that the ones who came did 
pretty well. They had strong theoretical grounding. It would 


have been hard to sort them out, but T.D. Lee had arranged for 
examinations to classify these people and that was a big help. 

Riess: What do you mean "sort them out"? 

Schawlow: Well, to find out which ones were really good. 

Riess: You mean at the point where they're applying? 

Schawlow: Yes. 

Riess: Where was T.D. Lee? 

Schawlow: He's a professor at Columbia, from China originally. He got a 
Nobel Prize in the 1950s for discovering the nonconservation of 
parity. Both he and C.N. Yang, who shared the prize with him, 
they've both come from China and they've done a lot to try and 
help Chinese physics. 

Summing up the Seventies 

Riess: When Ted Hansch came in 1970 the original whole balanceit ' s 
not like a balance of power, but something shifted. 

Schawlow: Yes, sure, the direction of things. 

We had some money for the first time. We had that 
equipment grant and tunable lasers had just been discovered, 
and he improved them considerably. But we could, for the first 
time, do some laser spectroscopy. Up until then we'd just been 
mostly studying the properties of materials related to lasers, 
we hadn't really been doing work on lasers so much except what 
Emmett did, or building lasers for special projects. So we 
switched over, really cut down working on solids and I think 
Gary Klauminzer was probably the last one to work on ions in 

Then I sort of started following up on some of the things 
that Hansch had started. Well, some things were my own. I had 
worked on Brillouin scattering, and also the intermodulated 
fluorescence, which was the way to get sensitive detection of 
weak lines which has been used by some other people too. 

Riess: In fact, the set of questions that you had initially asked as a 
graduate students were beginning to be answered at the end of 
your research. 







Yes, certainly getting rid of the Doppler broadening, that was 
pretty well under way with the saturation of intennodulated 
fluorescence and so on, and other methods of polarization and 

But it's the old story--a lot of things that were terribly 
difficult to do at one time, like when I was a student, become 
easy, but they're done. [laughs] So you have to keep on 
looking for other things. 

When Ted Hansch came did your role vis-a-vis students change? 

Well, he had his students and I had mine. And I didn't have 
much to do with his students. I guess at first even before he 
became associate professor there were some of them that were 
formally reporting to me but actually being supervised by Ted. 

It is true that toward the end I was really letting him 
have all the resources I could and really making do with things 
that he wasn't interested in, equipment that he was tired of. 
So he did cause some constraints on space and money, but still 
he was so good that I just really wanted him to have every 
opportunity that he could. And of course we were fighting to 
keep him because other places were trying to hire him away, 
Harvard and Yale among them, and Heidelberg, and then finally 
Munich got him. 

What was the financial situation in those years? 
equipment then. 

You had the 

I got the equipment grant just about the time he came, 
never got another one. 

but I 

We did have what the National Science Foundation claimed 
was the biggest grant in their atomic physics program. They 
were used to fifty thousand dollar grants and ours was probably 
about three hundred thousand. But it sure wasn't enough for 
all the things we wanted to do. We had to pay huge overhead on 
any salaries or any supplies. We had to pay employee benefits 
of something like twenty-five percent, and overhead on salaries 
after benefits, including the benefits, something like sixty 

I think it was true that if I hired a person it would cost 
me Just for his salary twice as much as I was paying him. So 
that made it very expensive. It was one reason why I stopped 
having any postdocs. If somebody came with their own money, 
that was all right, but I couldn't afford to hire them. 


After I retired, a man from the Office of Naval Research 
who had been helping us said that he wanted me to have seventy- 
five thousand a year so that I could hire a postdoc. Well, I 
figured if I hired a postdoc, I couldn't pay less than about 
thirty thousand for salary, and with overhead I think it would 
be over sixty thousand. That would leave very little money for 
equipment or supplies, and I just wasn't able to do it. 

Riess: Was that an area where you did battle with Stanford? 

Schawlow: No. I'm afraid I just took what I could get. I felt it was 
hopeless. Other people were trying to fight it, not I. The 
university wanted all the money they could get their hands on. 

Then of course they got into trouble with the government 
over charging too much. The Office of Naval Research had a 
representative at Stanford who could approve our payments, and 
usually these were people who'd go along quite nicely with 
whatever we wanted to do. But then they got a guy who wanted 
to make trouble and he caused a lot of trouble and he found a 
few skeletons in the Stanford closet, nothing to do with me, 
but they then cut their reimbursement rate for overhead 
substantially. I don't think it's ever gotten up to what they 
had before though it's still pretty high. 

News of the Nobel Prize Putting the Money to Work for Artie 

Riess: Let's go now to the happy subject of the Nobel Prize. Tell me 
about it, and also tell me what you did with your prize money. 

Schawlow: Well, first thing I heard of it was that I had this phone call 
at four o'clock in the morning from a radio reporter. He 
wanted to know first of all what had I done to get this Nobel 
Prize, and I couldn't tell because I had published a hundred 
and sixty-seven papers and I didn't know which combination they 
were honoring me for. In fact, it was some time quite late in 
the day before I got the actual citation, [laughter] 

Nowadays and before that, I think usually there's a phone 
call from the Swedish Academy. But I didn't get one. I did 
get a telegram from the Swedish ambassador I think, but it was 
days later that I got anything direct from the Academy. 

Riess: There is a picture of you and Aurelia on the telephone in your 
kitchen. I take it that was posed. 


Schawlow: Well, yes and no. I guess so. Anyway, that was early in the 
morning, and of course the phone calls started coming. Then 
the Palo Alto Times, I guess, wanted to send a photographer. 
So Aurelia insisted that I take the phone off the hook and get 

Schawlow: Yes. This reporter also asked me what I was going to do with 
the money. I told him I had an autistic son and that we were 
working with some others to try and set up a group home for 
autistic people. Well, actually, I did give five thousand 
dollars to a Peninsula Children's Center which was trying to 
plan something, but what they were planning just wasn't 
suitable, so we dropped out of that. They felt that you could 
just have a program for a few years, and autistic people are 
not going to be cured in a few years. 

So then we found a group home for Artie, and we offered to 

pay for an extra staff member. We paid them, I think, $2500 a 
month or something like that for some months. I think we spent 
over twenty thousand dollars on that. 

Well, of course we spent a few thousand dollars on the 
trip, because I took my wife and daughters and they needed six 
evening gowns. [laughter] They borrowed fur coats from 
various friends, so they didn't have to buy a fur coat which 
you couldn't use in Palo Alto. We didn't go the cheapest way. 
We stopped in London both ways, and in New York. We spent 
about seven thousand dollars on those expenses. So that 
accounts for about thirty-four thousand, and I'm sure the rest 
of it all went for things that Artie needed. I've spent 
hundreds of thousands on things for him. 

Riess: You used that as a public opportunity to talk about autism. 

Schawlow: Yes, I did, and it was appreciated by the Autistic Society. 
They gave me a plaque. 

A wonderful thing came out of it. When we went to 
Stockholm, we met Karin Stensland Junker. She was the mother 
of an autistic girl and had written a book about her daughter. 
Then she got a Ph.D. in clinical psychology working on that. 
She told us about a young man who had come to her office and he 
couldn't talk--he was twenty-four years oldbut he could type 
on the keyboard that looked about the size of a calculator, but 
it typed letters instead of numbers and it printed them out on 
a paper tape. 


She asked him, "Could I have some of your tapes?" And he 
replied, in Swedish of course, "No." She said, "Why not?" He 
said, "You can't read it when the sun shines." Well, it fades 
in sunlight, it was a thermal printing. 

I thought, "Gosh, if Art could do that!" He might be able 
to understand that, but we had no way of telling. 

Then when we came home, I was giving talks all over the 
country to various Autistic Society people. And in Memphis I 
told somebody about this and he said, "That sounds like a Canon 
Communicator," and gave me an address in Seattle. It turned 
out that they were just modifying it for special handicaps, 
like for people who needed to operate it with a stick in the 
mouth. But they told me where the American distributor was and 
it turned out that was a company that was about a mile away 
from my home. 

I went over there, and they would 've lent me one, but I 
knew it was going to be more difficult so I bought one for six 
hundred dollars. And it was a flop. He just hit XXX and ZZZ 
and so on. 

Well, we've told the full story in that article that we 
wrote about him. We tried various things. Finally it was a 
couple of years later, almost two years later, that he began to 
actually communicate with us. 

Riess: So first he resisted it? 

Schawlow: Yes. But then we tried other things, like trying to get him to 
pick out letters and put them into blocks where they would fit . 

Then we got this Texas Instruments Touch and Tell, where 
the synthesized voice asks, "Show me the red letter 'R'," 
something like that, and then if you get it then they say, 
"That's good," or something like that, and move on to the next. 

The first week he just didn't seem to know what it was all 
about. Next week, he did all right off, he knew the whole 
alphabet. Then we tried cards with pictures and with words, 
matching words to pictures. He could do that pretty well. 
Then we had him picking out words from a magazine page and he 
could do that too. 

Then we met a speech therapist who showed us how to use a 
communication board where you put the words on. You can make 
choices, like for snacks or Job tasks. You point to a word. 
We thought he might need pictures, but he didn't. With just 
the words, he could do it. So he obviously could read some. I 





guess we'd had another teacher for a short while who began to 
show us that he could recognize letters. That happened along 
there. I forget exactly where that came in. 

Then we had this first laptop computer, the Epson HX-20. I 
programmed it to show a word with a dash under each letter. 
Nothing would happen unless you pressed the right key, then the 
letter would appear. And at the end of the word, if he got the 
word complete, it would print it out on a strip printer that 
was built in like an adding machine printer. He loved that. 
He would tear off these things and stuff his pockets with these 
tapes until he had used up all the tape. 

But this was still not communicating. So then one day I 
thought, "Well, I'll let you choose what kind of pizza you 
want." We were at the park and we'd usually go for pizza after 
that. I put down cheese, sausage, and pepperoni. He chose 
sausage by pointing to it. I said, "Let's confirm that by 
typing it out." And he typed it out with my hand on his. 

Then it was just a week or two later that we were in the 
ice cream parlor, and he waved for something over in one 
direction. We acted dumb and said, "Let's go to the car and 
get the communicator. You can tell us." He typed out "shoes" 
and there was a shoe store there, so we bought him shoes, and 
that was a big breakthrough. 

Your hand on his, of course, is the controversial part of the 
whole business. 

Yes, I know. But that was the way to get his hand on the 
keyboard. And he still seems to want it. He doesn't usually 
want to point at anything without a hand on his . Very 
occasionally he forgets that he needs that and will do 
something. There have been some studies on how to achieve 

It's been hard for us because we'd only see him every few 
weeks for an hour or two and we wanted to get the 
communication. But I really wish we could work on independence 
because we're not always going to be around. Fortunately some 
other people have been able to pick it up and can get something 
out of it. Some, particularly Martha Leary, and Aurelia when 
she was alive, are very good, they can get a lot out of him. 
Otherswell, when he really wants something, he can tell them. 

He probably really wants you and that's the way of staying 





I guess so, but he doesn't tell me a lot. 
communicative . 

He ' s not very 

Here you were coming back from your Nobel Prize event and 
speaking around the country on autism. Receiving the prize 
also meant the beginning of another flood of speaking 

Yes, it was bad. 1 had been doing so many things, 1 got the 
flu quite bad in January of 1982. Then 1 got it again the 
following year. Too much travelling and being run down. Since 
then I've been taking flu shots and I've only had it once. But 
I find that flu shots and pneumonia shots are not totally 

Current Work 

Riess: Now, today, what are the questions you're still wishing, if you 
had time in your lab, you could answer? 

Schawlow: I got interested in trying to see these rare earth ions, which 
have fairly sharp lines even in solids because they're somewhat 
shielded from their neighbors, I wanted to see what they could 
tell us about metals, or conducting semi -metals. So I had 
students search for these lines. In fact, I just got the proof 
of an article that I've written for a memorial issue of 
Physica, the Swedish physics magazine, a memorial issue for 
George Series. 

I start off by saying that he had done some wonderful 
things on the details of spectral lines, but there were other 
things where you had to look. I said. "There's an old recipe 
for rabbit stew that starts, 'First, catch a rabbit.'" 
[laughter] In this case, we didn't know where these lines would 
be, we had to search. Unfortunately, nobody knows how to 
search over a wide range using lasers. They're more like too 
sharp a searchlight when you need a flood light. 

I would have liked to have taken a laser and studied some 
of these lines as they go through the superconducting 
transition. The superconductor theorists like Phil Anderson 
say this is not very interesting because these ions are not 
directly involved in the superconductivity. They have to be 
there somehow, but just the copper oxide layer is where the 
superconductivity is. That's what they say. 


Well, I don't think this is the most important thing but 
it's interesting, it's a puzzle. 

Riess: As it becomes simply less convenient to simply be in your lab, 
from parking to the other things that are going on in your 
life, do you find yourself becoming more of a theorist? 

Schawlow: No, I'll never be a theorist. A theorist is one who can do 

mathematical calculations. I can think about the physics, the 
theory in broad terms. That's all I can do. I'm not doing 
much of that, but I am doing a little of that. I'm trying to 
plow through where other people have plowed, and it's not 
likely that I'll discover anything worthwhile, but I'm still 
intrigued by the puzzles and try to think about them. 

Riess: Do you use your computer to get onto the physics websites? 

Schawlow: No, not at all. I don't know whether my kind of physics would 
be on there. Probably would. I've found some people post 
their papers on the net. I haven't tried. I should try for 
lasers and nonlocality and things like that. 

Riess: I think you should because if anyone can get plugged in, it's 

Schawlow: I guess so. You can certainly spend an infinite amount of time 
with computers. 


Schawlow: I've always told my students that to discover something new, 
you never have to know everything about a subject, you never 
can. All you have to do is recognize one thing that's not 

Riess: Charlie Townes said in the introduction to the book in your 

honor said that you had a role in the American Physics Society 
and other organizations in shaping policy for the world of 
physicists. 1 

Schawlow: Well, I don't I really had too much to do with it. I was on 
the various boards, director of the Optical Society and the 
Physical Society, and I was president of each of them. On the 
big committees maybe you can nudge things slightly in some 
direction- -actually the executive officers, or whatever they're 

'p. vii, Lasers, Spectroscopy and New Ideas, A Tribute to Arthur L. 
Schawlow, Springer Series in Optical Sciences, 1987. 


called, executive secretaries, are the people who really run 
those things . 

Riess: He must be referring to something. 

Schawlow: I can't think of anything terribly important, just to try and 
keep them on the right path. 

I did help to get the Optical Society more deeply into 
serious physics. There was one time they had a joint meeting 
of the Optical Society and the American Physical Society and I 
organized a really high level session on "What is light?" and 
got some really top people to give some talks. So, I think I 
sort of helped to raise the tone of the Optical Society, 
although I certainly didn't do it alone. There were a lot of 
other good people. 

The Physical Society? I don't know, I gave them whatever 
advice I could give, but I don't really think that I changed 
the direction appreciably. 

Riess: I thought perhaps it might have been vis-a-vis issues in 
military or war. 

Schawlow: No, I avoided them. I really was bad, I didn't. Most other 
presidents have pontificated on such subjects, but not me. 

Thinking in Classical Pictures 

Riess: You have certainly a reputationand I can tell from this oral 
historyas a terrific public speaker. That's a great gift. 

Schawlow: I don't know. I gradually gained confidence. 

It partly comes back to the way I think. I realize that 
even when I was a student that if I had any real ability, it 
was that I could look at a subject and say, "Now, what's really 
the important thing here? What's it all about? Never mind the 
details." And that's a good thing to do when you're trying to 
write a presentation, or a paper, or give a talk. If you can 
grasp what it's all about, then you can maybe make it clear and 
give the illusion to people that they understand it. 

I guess I told you I've some horrible experienceswell, 
they turned out all right. Like the first time I was invited 
to give a talk at the American Physical Society and I was on 
the program following Feynman. [laughter] 

Riess: You really wish to communicate what you are doing, too. 

Schawlow: I think so. As I say, I think gradually as you gain 

confidence, as you have some success, then you're willing to 
stick your neck out and make bolder statements and predictions. 

Riess: And somewhere I've written down, "Schawlow has little patience 
with abstract theory or tedious mathematical derivations." 

Schawlow: That's for sure. As I've sometimes said, I think in fuzzy 

pictures. [laughing] I'm not an artist, I can't draw anything, 
but I do think in pictures. They are probably not as clear or 
sharp as a person with more artistic ability could do, but I 
like to picture things. 

In some ways, I'm sort of out of step with the world 
because I guess I think more in classical pictures. I find 
quantum theory very puzzling. Well, everybody agrees it's 
puzzling now! But the orthodox view is that there's no use 
trying to think of concrete pictures for things you can't 
measure like what happens between here and there, when light 
is emitted and when it's absorbed. But I keep trying. 

Riess: Does fuzzy logic make it more acceptable to think in fuzzy 

Schawlow: No. Fuzzy logic just means that instead of having things 

always off or on, you can adjust them. This is the sort of 
thing we've always done as humans. Like when you turn your 
radio set on, you set the volume at the level you find 
convenient and not always full on or full off. I don't think 
there's much more to fuzzy logic than that, except that they're 
able to do it in a systematic computer way. 

Riess: Do you find chaos theory helpful in thinking about the world? 

Schawlow: No. The general idea certainly is true that some things the 
image of a butterfly starting a storm--it's true that a lot of 
things are easily tipped by a slight initiation one way or the 
other. But I don't think that really interacts much with 
anything I think about. 

A Few Last Stories to Tell 

Riess: I want to ask you a question that I don't usually ask, but I'd 
like to get it on the record. It's awkward to ask. 






That's all right. 

What would you like to have gotten out of having done the oral 

Well, I thought what I wanted to do was to have a summary of 
what I've done so that I could start writing my autobiography 
and have the facts down there and try put them into perhaps a 
little different shape, with maybe a few more jokes. [laughs] 
I mean, I've seen some funny things. But strangely enough, I'm 
feeling rather discouraged. I feel that now I've gone through 
this stuff, I don't think it's very interesting and I don't 
know how I can make myself face it. 

I think I've spent too much time trying to cover issues in 
physics while you are wishing to tell a more lighthearted 
version of your life. 

Yes, well, that could easily be done later. I don't know, I 
don't think I have the ability to write it, but I'm not sure. 
If I ever can get some time to think, I'll have to think about 
that. But there just seems to be an endless number of things 
that have to be done . 

For instance, I got a letter from a lady in Florida who 
wants to know if I know a school district in California where 
they allow facilitated communication. Well, I don't, but I 
can't really say simply that I don't. I'll have to do some 
digging and see if I can find something, find somebody that 
might know something. 

Riess: The autism research has been a secondary field of your life. 

Schawlow: Yes, it has. I've had a curiously semi-detached view of 

things. What works for me and for Artie is all I care about, 
really. But of course you can't really help one person without 
helping others. Like he couldn't live by himself, he has to 
have a group home, and when I help the group home I help him. 
I don't know. Well, I'll call a few people, see if I can get 
leads on that one. 1 

But there just seems to me an awful lot of stuff. For 
instance, I spend a lot of time sorting out my records and CDs, 
and then unfortunately getting new ones. 

'July 1997, Arthur Schawlow notes that he did find such a school 
district in California. 


Riess: About getting the jokes in, and the lightness, it's hard to 
testify to one's own wit and humor. 

Schawlow: Yes, well I have a few stale jokes that I keep using over and 
over again. Or I don't have jokes, really. I have a spiel 
that I use when I break balloons. 

There have been some funny things that have happened that I 
would like to include if I think of them as I go along, and I 
probably have included some. Not necessarily things that I 
did. There are some funny things that I've thought up and 
which I treasure and sort out. I'll crack jokes and sometimes 
they'll fall flat, in which case I won't reuse them. 

Riess: In the classroom? 

Schawlow: Sometimes. Sometimes in meetings. It's often good to lighten 
the meetings. When things get too serious, it helps to have a 
little bit of a joke. 


Schawlow: Things just occur to me on the spur of the moment. For 

instance, there was this talk about "death rays." So I made a 
slide from a picture in the encyclopedia of knights in shining 
armor and I called it "our laser countermeasures." The shiny 
metal would reflect most of the laser light. [laughter] 

I was being interviewed by a reporter and I said that as 
soon as there were any lasers the science fiction writers, "or 
newspaper reporters, as they're sometimes known," thought this 
was all for weaponry. [laughter] These things just kind of 
come out of the situation. 

[tape interruption] 




[Schawlow turns to his music collection] I have a machine that 
allows you to scan sheet music into it and transpose it and 
print it out in a different key. For clarinet, you know, you 
can take piano things and transpose them. If I ever do play 
the clarinet again. Right now it's just kind of speculation. 

Do you think you will get back to the clarinet? It might be 
good for your lungs . 

I don't really know. That's what the physical therapist said, 
I really ought to do it, for my lungs. I do a lot of just kind 
of sitting, staring at newspapers and magazines, things like 
that. I don't have a lot of energy. But I'm getting better. 


[Schawlow puts on a CD] I got this record--! used to go to 
New York several times a year and I would go, always, to Jimmy 
Ryan's, where usually Joe Muranyi was playing clarinet. He's 
Hungarian descent and speaks the Hungarian language and in 
recent years has been going back and forth to Hungary where 
he's a big hero as a jazzman who played with Louis Armstrong. 

[tape interruption] 

Schawlow: [ Schawlow reviews with Riess the spelling of the names of some 
Chinese physicists] Before we went to China we took a short 
course in Chinese in night school run by Foothill Junior 
College in Palo Alto. In China, everywhere we were we went to 
a Friendship Store. They have souvenirs and things. I would 
tell my wife "Wode chyan bugou"--my money's not enough, 

The course was taught by a nice old Chinese gentleman, Dr. 
P.F. Tao, who had gotten a Ph.D. in Berlin many years before. 
I liked that course so much that I thought, two years later, 
I'd go back and take a little more. 

Anyway, then we came across the word "chang" meaning "to 
sing," and also the word "chang" meaning "often." So I asked 
Mrs. Xia, who was then visiting in our lab, "How do you say, 
'We often sing Chinese songs?'" And she said, "Women tsang 
tsang jungwo ger." I told the teacher this and he said, "Oh 
yes, that's the Shanghai dialect." [laughter] Apparently the 
dialect all the way through the middle of China is something 
like that because people in Chungking were doing that too. 

When we were in China it was interesting listening to 
people on the street. We could occasionally make out a word. 
I really had very little vocabulary and we had not studied 
characters at all. In this night school Chinese class there 
were several people of Chinese origin, but they spoke Cantonese 
and they wanted to learn to speak Mandarin. 

That second attempt to learn Chinese came in the autumn of 
1981. In October I learned that I had to make the trip to 
Stockholm for the Nobel Prize and I had many new things to get 
done. So I went back to the class the next week and told Dr. 
Tao that I couldn't continue with the course. He said, "We 
understand, and we're greatly honored to have you. We would 
like to put on a banquet in your honor." 

So, two or three weeks later they had a banquet at a local 
Chinese restaurant. It was attended by that class and another, 
and there was an orchestra of students playing Chinese musical 
instruments. A student reporter for the Foothill Junior 




College newspaper was present at the event. A couple of weeks 
after that, an article appeared with the heading, "Foothill 
Dropout Honored for Nobel Prize." [laughter] 

The main trouble with learning to speak a foreign language 
is that when you say something, then they answer you, and then 
you're lost. You can carefully compose a sentence, but you 
never know what's going to happen. 

Did I tell you about my encounter with Italian? 

We were in Florence. My wife, who had studied some 
Italian--! had not, although I had listened to a record of 
Italian phrases insisted that I buy the tickets to Rome. So I 
went up to the counter--! had carefully preparedand I said, 
"Due bigletti per Roma, primo classe, con posti reservati" 
"two tickets to Rome first class with reserved seats." I had 
the time written down on a piece of paper. 

He said, "Si, oggi?" And I had no idea what he meant. 
Then he said, "Today?" [laughter] A perfect example of where 
you can get thrown by lack of vocabulary. 

Professor Schawlow, here is where the interview ends. 1 Are you 
content with our linguistic discussion as the final note? Or 
do you want to sum up in some way, as if you knew that you were 
having a last say? 

[written addition] Well, I always told my students that there 
are three rules for writing: (1) have something to say (that's 
the hardest part), (2) say it, and (3) stop. 

However, looking back, I have had some success and a lot of 
satisfaction in life. It has been hard work, and I have 
stupidly overlooked some good things that I might have found. 
Perhaps my focus was too narrow at times, but I felt that I had 
to concentrate on what seemed most important and yet 
attainable. The only fact that saved me was that others 
overlook things, and so, as I told my students, there are still 
lots of simple and beautiful things to be discovered. I really 
believe that. 

I did have some wonderful research collaborators and 
students, and they helped to make up for my deficiencies. 
Science is cumulative and many very able people have taken up 
some of my work, and carried it far beyond anything I imagined. 

J This final question to Arthur Schawlow was added and answered in the 
editing stage, after the interviews were concluded. 


Thus, while some of my results are properly forgotten, others 
have gone so far as to make me look a lot more prescient than I 
ever was. In all, physics has been intriguing, at times 
frustrating and compelling, but very worthwhile. I can't 
imagine doing anything else with my life. 

Transcriber: Lisa Vasquez 
Final Typist: Caroline Sears 


TAPE GUIDE --Arthur Schawlow 

Interview 1: August 14, 1996 

Tape 1, Side A 

Tape 1, Side B 

Tape 2, Side A 

Tape 2, Side B 

Interview 2: August 21, 1996 
Tape 3, Side A 
Tape 3, Side B 
Tape 4, Side A 
Tape 4, Side B 

Interview 3 
Tape 5 
Tape 5 
Tape 6 

September 4, 1996 
Side A 
Side B 
Side A 

Tape 6, Side B 

Interview 4: 
Tape 7, 
Tape 7 
Tape 8 

September 12, 1996 
Side A 
Side B 
Side A 

Tape 8, Side B 

Interview 5: October 30, 1996 
Tape 9, Side A 
Tape 9, Side B 
Tape 10, Side A 
Tape 10, Side B 
Insert from Tape 12, Side A 
Insert from Tape 12, Side B 
Insert from Tape 13, Side B 
Insert from Tape 14, Side A 

Interview 6: November 7, 1996 

Tape 11, Side A 

Tape 11, Side B 

Tape 12, Side A 

Interview 7: November 14, 
Tape 13, Side A 
Tape 13, Side B 
Tape 14, Side B 













Interview 8: November 26, 1996 


Tape 15, Side A 263 

Tape 15, Side B 271 

Tape 16, Side A 280 

Tape 16, Side B 

Tape 17, Side A 296 

Tape 17, Side B not recorded 


A Publications 302 

B Four pages excerpted from Toronto Jazz, A Survey of Live 

Appearances and Radio Broadcasts of Dixieland Jazz Experienced in 
Toronto During the Period 1948-1950, by Jack Litchfield. 316a 

C "From Maser to Laser", by Arthur L. Schawlow, in Impact of Basic 

Research on Technology, Kursunoglu and Perlmutter, editors, Plenum 
Press, New York-London, 1973. 317 

D "Masers and Lasers", by Arthur L. Schawlow, Fellow, Institute of 
Electrical and Electronics Engineers, from IEEE Transactions on 
Electron Devices, Vol. ED-23, No. 7, July 1976. 354 

E "Never Too Late, Communication With Autistic Adults", by Aurelia 
T. Schawlow and Arthur L. Schawlow, in Proceedings of the NSAC 
(now Autism Society of America) National Conference, July 1985. 361 

F "Our Son: The Endless Search for Help," by Aurelia T. Schawlow and 
Arthur L. Schawlow, in Integrating Moderately and Severely 
Handicapped Learners, Strategies that Work, Brady and Gunter, 
editors, Thomas Books, Springfield, Illinois, 1985. 370 


Publications by ARTHUR L. SCHAWLOW 

1. Nuclear Moments of Silver (M.F. Crawford, ALS, W.M. Gray, and F.M. Kelly), 

Phys. Rev. 75, 1112 (1949) (letter). 

2. Transmission and Reflection Coefficients of Aluminum Films for 

Interferometry (M.F. Crawford, W.M. Gray, ALS, and F.M. Kelly), 
J. Opt. Soc. Am. 39, 888 (1949). 

3. Electron-Nuclear Potential Fields from Hyperfine Structure (M.F. Crawford 

and ALS), Phys. Rev. 76, 1310, (1949). 

4. Nuclear Moments of 25 Mg (M.F. Crawford, F.M. Kelly, ALS, and W.M. Gray), 

Phys. Rev. 76, 1527 (1949) (letter). 

5. Hyperfine Structure and Nuclear Moments of 207 Pb (ALS, J.N.P. Hume, 

and M.F. Crawford), Phys. Rev. 76, 1876 (1949) (letter). 

6. Isotope Shift in the Resonance Lines of Zinc (M.F. Crawford, W.M. Gray, 

F.M. Kelly, and ALS), Can. J. Res., A, 28, 138 (1950). 

7. An Atomic Beam Source and Spectrograph for Hyperfine Structure. Nuclear 

Moments of Silver (M.F. Crawford, ALS, F.M. Kelly, and W.M. Gray), 
Can. J. Res., A, 28, 558 (1950). 

8. Nuclear Magnetic Moments and Similarity between Neutron and Proton States 

in the Nucleus (ALS and C.H. Townes), Phys. Rev. 82, 268 (1951) 
(letter) . 

9. Significance of the Results of Microwave Spectroscopy for Nuclear Theory, 

Ann. New York Acad. Sci . 35, 955 (1952). 

10. Microwave Spectrum and Structure of Re0 3 Cl (E. Amble, S.L. Miller, ALS, 

and C.H. Townes), J. Chem. Phys. 20, 192 (1952). 

11. Charge Distribution in Nuclei from X-Ray Fine Structure (ALS and 

C.H. Townes) , Science, 115, 284 (1952). 

12. Quadrupole Coupling Ratio of the Chlorine Isotopes (T.C. Wang, C.H. 

Townes, ALS, andA.N. Holden) , Phys. Rev. 86, 809 (1952) (letter). 

13. A Microwave Spectrum of the Free OH Radical (T.M. Sanders, Jr., ALS, 

G.C. Dousmanis, and C.H. Townes), J. Chem. Phys. 22, 245 (1954). 

14. Examination of Methods for Detecting OH (T.M. Sanders, Jr., ALS, G.C. 

Dousmanis, and C.H. Townes), J. Chem. Phys. 22, 245 (1954). 

15. Hyperfine Structure in the Spectrum of N 14 H 3 . I. Experimental Results 

(G.R. Gunther-Mohr, R.L. White, ALS, W.E. Good, and D.K. Coles), 
Phys. Rev. 94, 1184 (1954). 

16. Nuclear Quadrupole Resonances in Solid Bromine and Iodine Compounds, 

J. Chem. Phys. 22, 1211 (1954). 


17. Structure of the Intermediate State in Superconductors (ALS, B.T. 

Matthias, H.W. Lewis, and G.E. Devlin), Phys . Rev. Letters 95, 1344 
(1954) . 

18. Effect on X-Ray Fine Structure of Deviations from a Coulomb Field near 

the Nucleus (ALS and C.H. Townes), Phys. Rev. 100, 1273 (1955). 

19. Microwave Spectroscopy (C.H. Townes and ALS), McGraw-HillBook Company, 

New York (1955). (Reprinted by Dover Publication 1975). 

20. Structure of the Intermediate State in Superconductors, in Proceedings 

of the Conference de Physique des Basses Temperatures, CNRS, 
Paris 1955. 

21. Crystal Structure and Quadrupole Coupling of Cyanogen Bromide, BrCN 

(S. Geller and ALS), J. Chem. Phys. 23, 779 (1955). 

22. Structure of the Intermediate State in Superconductors, Phys. Rev. 

101, 573 (1956). 

23. Intermediate State Of Superconductors: Influence of Crystal Structure 

(ALS and G.E. Devlin), Phys. Rev. 110, 1011 (1958). 

24. Structure of the Intermediate State of Superconductors (ALS and G.E. 

Devlin), in Proceedings of the Fifth International Conference on 

Low Temperature Physics and Chemistry, Madison, Wisconsin, 1957, J.R. 

Dillinger, ed., University of Wisconsin Press (1958), p. 311. 

25. Penetration of Magnetic Fields through Superconducting Films, Phys. Rev. 

Letters 109, 1856 (1958). 

26. Infrared and Optical Masers (ALS and C.H. Townes), Phys. Rev. 112, 1940 

(1958) . 

27. Effect of the Energy Gap on the Penetration Depth of Superconductors (ALS 

and G.E. Devlin), Phys. Rev. 113, 120 (1959). 

28. Structure-Sensitivity of the High-Frequency NMR in Powdered 

Anntiferromagnetic MnF 2 (J.L. Davis, G.E. Devlin, V. Jaccarino, and 
ALS), J. Phys. Chem. Solids 10, 106 (1959). 

29. Superconductivity, in Experimental Methods in Physics, Academic Press, 

New York (1959), Vol. 6, p. 71. 

30. Intermediate State of Hard Superconductors (ALS, G.E. Devlin, and J.K. 

Hulm) , Phys. Rev. 116, 626 (1959). 

31. Electronic Spectra of Exchange-Coupled Ion Pairs in Crystals (ALS, D.L. 

Wood, and A.M. Clogston) , Phys. Rev. Letters 3, 271 (1959). 

32. Optical Detection of Paramagnetic Resonance in an Excited State of Cr 3 * 

in A1 2 3 (S. Geschwind, R.J. Collins, and ALS), Phys. Rev. Letters 
3, 545 (1959) . 

33. Self-Absorption and Trapping of Sharp-Line Resonance Radiation in Ruby 

(F. Varsanyi, D.L. Wood, and ALS), Phys. Rev. Letters 3, 544 (1959). 


34. Optical Detection of Paramagnetic Resonance in Crystals at Low Temperature 

(J. Brosset. S. Geschwind, and ALS), Phys . Rev. Letters 3, 548 
(1959) . 

35. Infrared and Optical Masers, in Quantum Electronics, Columbia University 

Press, New York (1960), p. 553. 

36. Coherence, Narrowing, Directionality, and Relaxation Oscillations in the 

Light Emission from Ruby (R.J. Collins, D.F. Nelson, ALS, W.Bond, 
C.G.B. Garett, and W. Kaiser), Phys. Rev. Letters 3 (1960). 

37. Infrared and Optical Masers, Bell Laboratories Record 38, 403 (1960). 
37A. Infrared and Optical Masers, J. Am. Soc. Naval Engrs . 73, 45 (1961). 

38. Optical Masers, Northeast Electronics Research & Engineering Record, 

158 (1960). 

39. Zeeman Effect of the Purely Cubic Field Fluorescence Line MgO:Cr 3 * 

Crystals (S. Sugano, ALS, and F. Varsanyi), Phys. Rev. 120, 2045 
(1960) . 

40. Corbino Disk (D.A. Kleinman and ALS) , J. Appl. Phys. 31, 276 (1960). 

41. Simultaneous Optical Maser Action in Two Ruby Satellite Lines (ALS 

and G.E. Devlin), Phys. Rev. Letters 6, 96 (1961). 

42. Nuclear Quadrupole Resonance in an Antiferromagnet (J.C. Burgiel, 

V. Jaccarino, and ALS), Phys. Rev. 122, 429 (1961). 

43. Strain-Induced Effects on the Degenerate Spectral Line of Chromium in 

MgO Crystals (ALS, A.H. Piksis, and S. Sugano), Phys. Rev. 122, 
1469 (1961) . 

44. Infrared and Optical Masers, Sol. St. J. 2, 21 (1961). 

45. Optical Masers, Sci. Am. 204, 52 (1961). 

45A. Optical Masers, Usp. Fiz. Nauk. 75, 569 (1961). 

45B. Optical Masers, in Akceleratory, Reaktory, Lasery, Panstwowe Wydawnictwo 
Naudowe, Warsaw (1964). (Reprinted). 

46. Fine Structure and Properties of Chromium Fluorescence in Aluminum and 

Magnesium Oxide, in Advances in Quantum Electronics, J.R. Singer, 
ed., Columbia University Press, New York (1961), p. 50. 

47. Composite Rod Optical Maser (G.E. Devlin, J. McKenna, A.D. May, and ALS), 

Appl. Opt. 1, 11 (1962) . 

48. Fine-line Spectra of Chromium Ions in Crystals, J. Appl. Phys. 

Suppl. 33, 395 (1962). 

49. Masers, in Collier's Encyclopedia (1962), p. 493. 

49A. Masers, Electro-Technology, J. Soc. Elec. Engr., Electronics and Radar 
Development Establishment, Bangalore, 6, 199 (1962) . (Reprinted) . 


50. Lasers, Encyclopedia of Science and Technology, McGraw-Hill Book 

Company, New York (revised-1969) , p. 406 a-d. 

50A. Optical Masers (P. Kisliuk and ALS) , in McGraw-Hill Encyclopedia of 

Science and Technology Yearbook, McGraw-Hill Book Company, New York 
(1962) . p. 380. 

51. Optical Masers, in Proceedings of 1961 London Conference on Optical 

Instruments and Techniques, K.J. Habell, ed., Chapman and Hall, 
London {1962} . p. 431. 

52. Coherent Light for Communications, in Proceedings of the Symposium on 

Tracking and Command of Aerospace Vehicles, Institute of Aerospace 
Sciences, New York (1962) . 

53. Tilted Plate Interferometry with Large Plate Separations (H.W. Moos, 

G.F. Imbusch, L.F. Mollenauer, and ALS) , Appl . Opt. 2, 817 (1963). 

54. Optical Masers (Lasers), (ALS and H.W. Moos), in McGraw-Hill Encyclopedia 

of Science and Technology Yearbook, McGraw-Hill Book Company, 
New York (1963) . 

55. Crystals and Light, Stanford Research Inst. J. 6, 3 (1962). 

56. Widths and Positions of Sharp Optical Lines in Solids, in Quantum 

Electronics III, Proceedings of the Third International Conference, 
Paris, 1963, P. Grivet and N. Bloembergen, eds ., Columbia 
University Press, New York (1964), p. 645. 

57. Energy Levels in Concentrated Ruby (P. Kisliuk, ALS, and M.D. Sturge) , in 

Quantum Electronics III, Proceedings of the Third International 
Conference, Paris, 1963, P. Grivet and N. Bloembergen, eds., 
Columbia University Press, New York (1964), p. 51. 

58. The High Gain Laser as a Wavelength Standard (L.F. Mollenauer, G.F. 

Imbusch, H.W. Moos, ALS, and A.D. May), in Proceedings of the 
Symposium on Optical Masers, Polytechnic Institute of Brooklyn, April 
16-19, 1963, J. Fox, ed., Polytechnic Press, Brooklyn, New York 
(1963), p. 51. 

59. Enhanced Ultraviolet Output from Double-Pulsed Flash Lamps (J.L. Emmett 

and ALS), Appl. Phys . Letters 2, 204 (1963). 

60. Advances in Optical Masers, Sci . Am. 209, 34 (1963). 

60A. Advances in Optical Masers, Usp. Fiz. Nauk 81, 745 (1963) . (Reprinted) 

60B. Advances in Optical Masers, abridged translation "Le Applicazioni 
Pratiche del Laser" (Sapere, no. 650, p. 102 ((1964). 

61. Optical and Infrared Masers, Contemp. Phys. 5, 81 (1963). 

62. Temperature Dependence of the Width and Position of the 2 E- 4 A 2 

Fluorescent Lines of Cr 3 * and V 2 * in MgO (G.F. Imbusch, W.M. 

Yen, ALS, D.E. McCumber, and M.D. Sturgge) , Phys. Rev. 133, A1029 

(1964) . 


63. Optically Pumped K-.-. ~ers and Solid State Masers, in Proceedings of the 

International School of Physics "Enrico Fermi," Course XXXI, 
Quantum Electronics and Coherent Light, Varenna, Italy, 1963, 
P. A. Miles, ed., Academic Press, New York (1964). 

64. Lasers and Coherent Light, Phys . Today 17, 28 (1964). 

65. Direct Measurement of Xenon Flashtube Opacity (J.L. Emmett, ALS, E.H. 

Weinberg), J. Appl . Phys. 35, 2601 (1964). 

6t . Phonon-Induced Relaxation in Excited Optical States of Trivalent 

Praseodymium in LaF 3 (W.M. Yen, W.C. Scott , and ALS), Phys. Rev. 
136, A271 (1964) . 

67. Isotope Shifts in the R Lines of Chromium in Ruby and MgO (G.F. Imbusch 

W.M. Yen, ALS, G.E. Devlin, and J.P. Remeika) , Phys. Rev. 136, A271 

(1964) . 

68. A Portable Demonstration Laser (K.H. Sherwin and ALS), July, 1964, 

(Not for publication) . 

68A. How the Ruby Laser Works, Popular Science, November 1964, taken in part 
from "A Portable Demonstration Laser." 

69. Fluorescence of MgO:Cr 3 * Ions in Non-Cubic Sites (G.F. Imbusch, ALS, 

A.D. May, and S. Sugano) , Phys. Rev. 140, A830 (1965). 

70. Lasers, Science 149, 13 (1965). 

71. Lasers (H.G. Freie and ALS), in Advanced Optical Techniques, A.C.S. van 

Heel, ed., North-Holland Publishing Company (1967), p. 467. 

72. Measuring the Wavelength of Light with a Ruler, Am. J. Phys. 33, 922, 

(1965) . 

73. Observation of a Spin Wave Sideband in the Optical Spectrum of MnF 2 

(R.L. Greene, D.D. Sell, W.M. Yen, ALS, and R.M. White), Phys. Rev. 
Letters 15, 656 (1965) . 

74. Lasers, in the Symposium in International Ophthalmology Clinics (A 

Quarterly Book Series), Little, Brown and Company (1966), 6, No. 2, 
p. 241. 

75. Effect of Ultraviolet Pumping on Ruby Laser Output (R.L. Greene, J.L. 

Emmett, and ALS), Appl. Opt. 5, 350 (1966). 

76. Magnetic Effects in the Optical Spectrum of MnF 2 (D.D. Sell, R.L. Greene, 

W.M. Yen, ALS, and R.M. White) in Proceedings of the Conference on 
Magnetism and Magnetic Materials, 1965, in J. Appl. Phys. 37, 1229 

(1966) . 

77. Beam of the Future, in Science Year, The World Book Science Annual 1965, 

Field Enterprises Education Corporation (1965), p. 167. 


78. Far Infrared Spectra of V 4+ and Co 2 * Single Ions in Corundum (J. Y. Wong, 

M. J. Berggren, and ALS) ) , in Proceedings of the Conference on 
Optical Properties of Ions in Crystals, 1966, H. M. Crosswhite and H. 
W. Moos, eds . , Interscience Publishers, New York (1967), p. 383. 

79. Far Infrared Spectra of Al 2 3 :Ti 3+ ( E. D. Nelson, J. Y. Wong, 

andALS), Phys . Rev. 156, 298 (1967). 

80. Far Infrared Spectra of Al 2 3 :Cr 3+ and Al 2 3 :Ti 3+ ( E. D. Nelson, J. Y. 

Wong, and ALS), in Proceedings of the Conference on Optical 
Properties of Ions in Crystals, 1966, H. M. Crosswhite and H. W. 
Moos, eds ., Interscience Publishers, New York (1967), p. 375. 

81. Thermal Shifts in the Energy Levels of LaF 3 :Nd 3+ (S.A. Johnson, H.G. 

Freie, ALS, and W.M. Yen), J. Opt. Soc. Am. 57, 734 (1967). 

82. Spontaneous Emission from a Helium-Neon Laser as a Convenient Wavelength 

Standard (J.L. Rapier, H.H. Heimple, andALS), Am. J. Phys. 35, 890 
(1967) . 

83. Selective Laser Photocatalysis of Bromine Reactions (W.B. Tiffany, H.W. 

Moos, andALS), Sci. 157, 40 (1967). 

84. Piezospectroscopic Studies of Exchange-Coupled Cr 3 * Ion Pairs in Ruby 

(L.F. Mollenauer andALS), Phys. Rev. 168, 309 (1968). 

85. Lasers and Coherent Light, Am. Sci. 55, 197 (1967). 

86. Transverse Stimulated Emission in Liquids (J.L. Emmett and ALS), 

Phys. Rev. 170, 358 (1968). 

87. Far Infrared Spectrum of A1 2 3 :V 4+ (J.Y. Wong, M.J. Berggren, and ALS), 

J. Chem. Phys. 49, 835 (1968). 

88. Spectroscopic Studies of SrTi0 3 Using Impurity Ion Probes (S.E. Stokowski 

andALS), Phys. Rev. 178, 457 (1969). 

89. Laser Light, Sci. Am. 219, 120 (1968). 

90. Dielectric-Related Optical Line Shifts in SrTi0 3 :Cr 3+ (S.E. Stokowski 

andALS), Phys. Rev. 178, 464 (1969). 

91. Electric-Field Effects on the Spectrum of Chromium in Strontium Titanate 

(S.E. Stokowski andALS), Phys. Rev. Letters 21, 965 (1968). 

92. Lasers and Light, readings from Scientific American, with Introductions 

by A.L. Schawlow, W.H. Freeman and Company, Incorporated, 
San Francisco (1969) . 

93. Plasma Refractive Effects in HCN Lasers (B.W. McCaul and ALS), in 

Proceedings of the Second Conference on Lasers, Annals of the 
New York Academy of Sciences 168, 3 (1970), p. 697. 


94. Lasers and Their Light, in Laser Photocoagulation and Retinal Angiography, 

by H.C. Zweng, H.L. Little, and R.B. Peabody, The C.V. Mosby 
Company, Saint Louis (1969), p. 3. 

95. Design and Analysis of Flashlamp Systems for Pumping Organic Dye Lasers 

(J.F. Holzrichter and ALS), in Proceedings of the Second Conference 
on Lasers, Annals of the New York Academy of Sciences 168, 3 
(1970), p. 703. 

96. Is Your Research Moral? Physics Today 22, 118 (1969). 

97. Lasers: The Old Dream and the New Reality, preface for book on Laser 

Applications, by W.V. Smith, Artech House, Incorporated (1970) . 

98. Polarized Fluorescence Study of Cr 3+ Through a Stress-Induced Phase 

Transition in SrTi0 3 (T.S. Chang, J.F. Holzrichter, G.F. Imbusch, 
and ALS), Sol. St. Comm. 8, 1179 (1970). 

99. Direct Observation of Single-Domain SrTi0 3 (T.S. Chang, J.F. Holzrichter, 

G.F. Imbusch, and ALS) , Appl . Phys. Letters 17, 6 (1970). 

100. Depolarized Light Scattering from Liquid Bromine (M.D. Levenson and ALS), 

Opt. Comm. 2, 4 (1970) . 

101. Cubic to Trigonal Stress Induced Phase Transition in SrTi0 3 (L.S. Wall, 

M. Rokni, and ALS), Sol. St. Comm. 9, 573 (1971). 

102. Laser Action of Dyes in Gelatin (T.W. Hansch, M. Pernier, and ALS), 

IEEE J. Quant. Electr. QE-7, 45 (1971). 

103. Dispersion in C 6 H 6 and C 6 D 6 (M.S. Sorem and ALS), Phys. Letters 33A, 268 

(1970) . 

104. Image Amplification by Dye Lasers (T.W. Hansch, F. Varsanyi, and ALS), 

Appl. Phys. Letters 18, 108 (1971). 

105. Complete Hyperfine Structure of a Molecular Iodine Line (T.W. Hansch, 

M.D. Levenson, and ALS), Phys. Rev. Letters 26, 946 (1971). 

106. Magnetization Induced by Optical Pumping in Antiferromagnetic *MnF 2 

(J.F. Holzrichter, R.M. Macfarlane, and ALS), Phys. Rev. Letters 26, 
652 (1971). 

107. An Image Orthicon Spectrograph with Computer Control (S.A. Johnson, 

W.M. Fairbank Jr., and ALS), Appl. Opt. 10, 2259 (1971). 

108. High Resolution Saturation Spectroscopy of the Sodium D Lines with a 

Pulsed Tunable Dye Laser (T.W. Hansch, I.S. Shahin and ALS), Phys. 
Rev. Letters 27, 707 (1971). 

109. From Maser to Laser, in The Impact of Basic Research on Technology, 

B. Kursunoglu and A. Perlmutter, eds., Plenum Press (1973), p. 113. 


110. Saturation Spectroscopy of Molecular londine Using the 5017A Argon 

Laser Line (M.S. Sorem, M.D. Levenson, and ALS) , Phys . Letters 37A, 
33 (1971). 

111. Spectroscopy with Tunable Lasers in the Visible Region, in Proceedings 

of the Esfahan Symposium on Fundamental and Applied Laser Physics, 
Esfahan, Iran, August /September 1971. 

112. Measurements of the Kinetic Energy of Free Positronium Formed in MgO 

(S. M. Curry and ALS), Phys. Letters 37A, 5 (1971). 

113. Lasers: The Light Fantastic, in Physical Science Today, Communications 

Research Machines, Incorporated (1973), p. 523. 

114. Optical Resolution of the Lamb Shift in Atomic Hydrogen by Laser 

Saturation Spectroscopy (T. W. Hansch, I. S. Shahin, and ALS), Nature 
235, 63(1972). 

115. Hyperfine Interaction in Molecular Iodine (M. D. Levenson and ALS), 

Phys. Rev. A6, 10 (1972). 

116. Saturation Spectroscopy in Molecular Iodine by Intermodulated Fluorescence 

(M. S. Sorem and ALS), Opt. Comm. 5, 148 (1972). 

117. Ultrasensitive Response of a CW Dye Laser to Selective Extinction 

(T. W. Hansch, ALS, P. E. Toschek) , IEEE J. Quant. Electr. QE8, 802 
(1972) . 

118. Nuclear Quadrupole Coupling of the 1 Z +9 and 2IT Du States of Molecular 

Iodine (M. S. Sorem, T. W. Hansch, and ALS), Chem. Phys. Letters 17, 
300(1972) . 

119. Simple Dye Laser Repetitively Pumped by a Xenon Ion Laser (T. W. Hansch, 

ALS, and P. Toschek), IEEE J. Quant. Electr. QE-9, 553 (1973). 

120. Lasers - Present and Future, in Proceedings of the Royal Institution, 

1973, England, February 16, 1973. 

121. Hyperfine Quantum Beats Observed in Cs Vapor under Pulsed Dye Laser 

Excitation (S. Haroche, J. A. Paisner, and ALS), Phys. Rev. Letters 
30, 948 (1973). 

122. Measuring the Diameter of a Hair by Diffraction (S. M. Curry and ALS), 

Am. J. Phys. 42, 412 (1974). 

123. The Better To See..., in The Greatest Adventure, E. H. Kone and 

H. J. Jordan, eds . , Rockefeller University Press (1974), p. 176. 

124. Two-photon Spectroscopy of Na 3s - 4d Without Doppler Broadening using 

a CW Dye Laser (T. W. Hansch, K. C. Harvey, G. Meisel, and ALS), 
Opt. Comm. 11, 50 (1974) . 

125. Lasers and Masers, in Encyclopedia Britannica (1974), p. 686. 

126. Observation of Zeeman Quantum Beats in Molecular Iodine (R. Wallenstein, 

J. A. Paisner, and ALS) , Phys. Rev. Letters 32, 1333 (1974). 


127. Isotope Separation by Selective Unimolecular Photoisomerization 

(J. I. Brauman, T. J. O'Leary, and ALS) , Opt. Comm. 12, 223 (1974). 

128. Absolute Measurement of Very Low Sodium Vapor Densities Using Laser 

Resonance Fluorescence (W. M. Fairbank, Jr., T. W. Hansch, and ALS), 
J. Opt. Soc. Am. 65, 199 (1975). 

129. Excited State Absorption in Ruby, Emerld, and MgO: Cr 3+ (W. M. Fairbank, 

Jr., G. K. Klauminzer, and ALS) , Phys . Rev. 11, B60 (1975). 

130. Cooling of Gases by Laser Radiation (T. W. Hansch and ALS) Opt. Comm. 

13, 68 (1975). 

131. Measurement of the Stark Effect in Sodium by Two-Photon Spectroscopy 

(K. C. Harvey, R. T. Hawkins, G. Meisel, and ALS), Phys. Rev. Letters 
34, 1073 (1975). 

132. Masers and Lasers, IEEE Electr. Devices, ED-23, 773 (1976). 

133. Identification of Absorption Lines by Modulated Lower-Level Population: 

Spectrum of Na 2 (M. E. Kaminsky, R. T. Hawkins, F. V. Kowalski, and 
ALS), Phys. Rev. Letters 36, 671 (1976). 

134. Simplification of Spectra by Polarization Labeling (R. Teets, 

R. Feinberg, T. W. Hansch, and ALS), Phys. Rev. Letters 
37, 683 (1976) . 

135. Digital Wavemeter for C.W. Lasers (F. V. Kowalski, R. T. Hawkins, 

and ALS), J. Opt. Soc. Am. 66, 965 (1976). 

136. Lasers, in Science Technology, and the Modern Navy, Thirtieth Anniversary 

1946-1976, Office of Naval Research, Arlington, Virginia (1976) . 

137. Ground State Relaxation Measurements by Laser-Induced Depopulation 

(R. Feinberg, R.E. Teets, J. Rubbmark, and ALS), J. Chem. Phys. 

66, 4330 (1977). 

138. Stark Effect Study of Excited States in Sodium Using Two-Photon 

Spectroscopy (R.T. Hawkins, W.T.Hill, F.V. Kowalski, ALS, and 
S.Svanberg), Phys. Rev. A15, 967 (1977). 

139. Lasers, Light and Matter, Frederic Ives Medal Address, J. Opt. Soc. Am. 

67, 140 (1977). 

140. Laser Interactions with Materials, in Proceedings of the LASER-77 

Opto-Electronic Conference, June 21-24, 1977, Munich, Germany 
(in press) . 

141. Saturated-Interference Spectroscopy (F.V. Kowalski, W.T.Hill, and ALS), 

Optics Letters 2, 112 (1978). 

142. An Improved Wavemeter for CW Lasers (F.V. Kowalski, R.E. Teets, 

W.Demtroder, and ALS), J. Opt. Soc. Am. 68, 1611 (1978). 


143. Twenty Years of Laser Physics (ALS), in Proceedings of LASER-78 

International Conference Mount Royal Hotel: London, 9-10 March 
(1978) . 

144. Laser Spectroscopy of Atoms and Molecules, Science 202, (1978), pp. 141-7. 

145. The Spectrum of Atomic Hydrogen (T.W. Hansch, G.W. Series, and ALS), 

Scientific American 240, No. 3, 94(1979) 

146. Polarization Labeling Spectroscopy of N0 2 , (R.E.Teets, N.W.Carlson, and 

ALS), J. Molec. Spectro., 78, 415 (1979). 

147. Doppler-Free Intermodulated Opto-Galvanic Spectroscopy (J.E.Lawler, 

A.I.Ferguson, J.E.M. Goldsmith, D.J.Jackson, and ALS), Physical 
Review Letters, 42, 1046 (1979). 

148. Precision Interferometer Calibration Technique for Wavelength 

Measurements: Iodine Wavelengths at 633 nm and H (J.E.M. Goldsmith, 
E.W.Weber, F. V. Kowalski, and ALS), Appl . Opt. 18, 1983 (1979). 

149. Identification of Excited States in Na 2 by Two-Step Polarization Labeling 

(N.W.Carlson, F.V. Kowalski, R.E.Teets, and ALS), Opt. Comm. 29, 302 
(1979) . 

150. Lasers: The Practical and the Possible, Stanford Magazine 7, 24 (1979). 

151. Doppler-Free Two-Photon Optogalvanic Spectroscopy (J.E.M. Goldsmith, 

A.I.Ferguson, J.E.Lawler, and ALS) , Optics Letters 4, 230 (1979). 

152. Doppler-Free Optogalvanic Spectroscopy (J.E.Lawler, A.I.Ferguson, 

J.E.M. Goldsmith, D.J.Jackson, and ALS), in Proceedings of the Fourth 
International Conference on Laser Spectroscopy, June 11-14, 1979, 
Garching, West Germany. 

153. Some Methods of Laser Spectroscopy, in Proceedings of the International 

Conference on the Physics of Electronics and Atomic Collisions, 
IPEAC 1979, N.Oda and K.Takayanagi, eds., Aug. 29-Sept. 4, 1979, 
Kyoto, Japan. 

154. The Laser Revolution, in Proceedings of the Fourth National Quantum 

Electronics Conference, Sept. 19-21, 1979, Edinburgh, Scotland. 

155. Sensitive Intracavity Absorption At Reduced Pressures (W. T. Hill III, 

R.A. Abreu, T.W. Hansch and A.L.S.), Optics Comm. 32, 96 (1980). 

156. Superradiance Triggering Spectroscopy (N.W. Carlson, D.J. Jackson, 

A.L.S., M. Gross and S. Haroche) , Optics Comm. 32, 350 (1980). 

157. Identification of Rydberg States in Na 2 , by Two-Step Polarization 

Labeling (N.W. Carlson, A.J. Taylor, and A.L.S.), Phys . Rev. Lett. 
45, 18 (1980). 

158. Polarization Intermodulated Excitation (POLINEX) Spectroscopy 

of Helium and Neon (T.W. Hansch, D.R. Lyons, ALS, A. Siegel, 
A-Y. Wang, and G-Y. Yan, Opt. Comm. 37, 87 (1981). 



159. Two-Step Polarization Labeling of Excited States of Na 2 (N.W. Carlson, 

A.J. Taylor, K.M. Jones, and ALS) , Phys. Rev. A24, 822 (1981) 

160. Doppler-Free Radiofrequency Optogalvanic Spectroscopy (D.R. Lyons, 

ALS, and G-Y. Yan) , Opt. Comm. 38, 35 (1981). 

161. A Study of the Excited 1 Z* 9 States in Na 2 (A.J. Taylor, K.M. Jones, 

andALS), Opt. Comm. 39, 47 (1981). 

162. Two-Photon Line Shapes with Near-Resonant Enhancement (H-R. Xia, 

G-Y. Yan, andALS), Opt. Comm. 39, 153 (1981). 

163. Selective Spectrum Simplification by Laser Level Labeling 

(N.W. Carlson, K.M. Jones, G.P. Morgan, ALS, A.J. Taylor, H-R. Xia, 
and G-Y Yan) , in Laser Spectroscopy V, Proceedings of the V 
Conference on Laser Spectroscopy, A.R. McKellar, T. Oka, and B.P. 
Stoicheff, eds., Springer-Verlag, New York (1981), p. 51. 

164. Polarization Intermodulated Excitation (POLINEX) Spectroscopy 

of Excited Atoms (Ph. Dabkiewicz, T.W. Hansch, D.R. Lyons, 

ALS, A. Siegel, Z-Y. Wang, and G-Y. Yan), in Laser Spectroscopy V, 

Proceedings of the V Conference on Laser Spectroscopy, 

A.R. McKellar, T. Oka, and B. P. Stoicheff, eds. Springer-Verlag, 

New York (1981) , p. 178. 

165. Spectral Structure of Continuous-Wave Two-Photon Transitions 

in Na (G.P. Morgan, H-R. Xia, and ALS), J. Opt. Soc. Am. 
72, 315 (1982). 

166. A Multiple-Wedge Wavemeter for Pulsed Lasers, (L.-S. Lee, and ALS), 

Optics Letters 6, 610 (1981). 

167. Simplifying Spectra by Laser Level Labeling, in the Proceedings of 

the International Colloquium on Molecular Spectroscopy, 
Stockholm, Sweden, May 11-15, 1981, also Physica Sripta 
25, 333 (1982). 

168. Spectroscopy in a New Light, Nobel Prize Lecture, in Les Prix Nobel, 

Nobel Foundation, Stockholm, 1982, 

168A Spectroscopy in a New Light, Reviews of Modern Physics 54, 687 (1982) 
168B Spectroscopy in a New Light, Science 217, 9 (1982) 

168C Fortechritte in der Laserspektroskopie, Naturwissenschaftliche 
Rundschau, 36, 247 (1983). 

168D Spectroscopy in a New Light, Uspekhi Fizicheskii Nauk (USSR) 
138, 205 (1982) . 

168E. Spectroscopy in a New Light, Postepy Fizyki (Poland) 
Tom 34, Zeszyt 4 (1983) . 

168F. Spectroscopy in a New Light, Czechoslovak Journal of Physics, 
Section A, Volume 33 (1983) . 



169. Ultraviolet Sum-Frequency Generation Utilizing Optical Pair 

Interactions in Solids (S.C.Rand, L.-S.Lee and ALS), 
Opt. Comm. 42, 179 (1982). 

170. Spectroscopy: Present and Prospects, in New Techniques of Optical 

and Infrared Spectroscopy, The Royal Society, 
London (1982), p. 219. 

170A. Spectroscopy: Present and Prospects, Phil. Trans. Roy. Soc. London, 
Series A, 307, 685 (1982). 

171. Lasers and Physics: A Pretty Good Hint, Physics Today 35, 46 (1982). 

172. Concluding Remarks, in Atomic Physics 8, I.Lindgren, A.Rosen, 

and S.Svanberg, eds, Plenum Press, New York (1983), p. 565. 

173. A Scanning Pulsed Polarization Spectrometer Applied to Na 2 , 

(A.J.Taylor, K.M.Jones, and ALS) , J. Opt. Soc. Am. 73, 994 (1983) 

174. Lasers and Their Uses (Charles H. Davis Lecture Series, Fall 1983), 

sponsored by Naval Studies Board, National Research Council, 
Academy Press, Washington (1983). 

175. Advances in Laser Spectroscopy, Interdisciplinary Science Reviews, 

Volume 9, Number 1, 59 (1984). 

176. Lasers in Historical Perspective, IEEE J. Quant. Electr., 

Centennial Issue (1984). 

177. Cascade Stimulated Emission in the Sodium Dimer (Z-G. Wang, Y-C.Wang, 

G.P.Morgan, and ALS) , Opt. Comm. 48, 398 (1984). 

178. Cooperative Energy Transfer Among Pr 3+ Ions in LaF 3 (L.-S.Lee, 

S.C.Rand, and ALS, Phys . Rev. B 29, 6901 1984). 

179. Generation of Coherent UV Radiation by Optical Wave-Mixing Processes 

in Atomic Potassium, (P. -L.Zhang, Y. -C.Wang, and ALS), 
J. Opt. Soc. Am. Bl, 9 (1984). 

180. Laser Spectroscopy, Past, Present, and Perhaps Future, in 

Proceedings of the International Conference on Lasers "82, 
STS Press, McLean, Virginia (1983), p. 1. 

181. Three-Photon-Excited Fluorescence Detection of Atomic Hydrogen 

in an Atmospheric-Pressure Flame (M.Alden, ALS, S.Svanberg, 
W.Wendt, and P. -L.Zhang), Optics Letters 9, 211 (1984). 

182. Two-Photon Resonant Optical Processes in Atomic Potassium 

(P. -L.Zhang and ALS), Canadian J. of Physics, 62, 1187 (1984) 

183. Laser Emission from Double-Minimum State (2) 1 + u to(2) 1 Z% by 

Optical Pumping in Sodium Dimer (Z. -G.Wang, H.-R.Xia, L.-S.Ma, 
Y. -Q.Lin, I. -S.Cheng, and ALS) in Proceedings of the 
International Conference on Lasers, LASERS '84, STS Press, 
McLean, Virginia (1985) . 



184. Comment of the Asymmetry Observed in Intracavity Absorption Line 

Profiles (W.T.Hill III, T.W.Hansch, andALS), accepted, 
Applied Optics, September, 1985. 

185. Lasers and Mankind, Franklin Lectures in Science and Humanities, 

Auburn University, Alabama, May 6, 1985. 

186. Laser Spectroscopy Using Beam Overlap Modulation (T.P.Duffey, 

D.Kammen, ALS, S.Svanberg, H.-R.Xia, G. -G.Xiao, and G.-Y.Yan), 
Optics Letters, 10, 597 (1985). 

187. 25 Years of Lasers, Encyclopedia Britannica Yearbook of Science and 

the Future, 1985. 

188. High-Contrast Doppler-Free Transmission Spectroscopy, (S.Svanberg, 

G.-Y.Yan, T.P.Duffey, andALS), Optics Letters, 11, 138 (1985). 

189. Two-Photon Resonances in a Sodium-Potassium Mixed Alkali Vapor 

(G.P.Morgan and ALS), J. Opt. Soc. Am. B, 1033 (1986). 

190. Saturation Spectroscopy for Optically Thick atomic Samples, 

(S. Svanberg, G.-Y.Yan, T.P. Duffey, W.-M. Du, T.W. Hansch and 
ALS), J. Opt. Soc. Am. B, 462 (1987). 

191. Principles of Lasers, in Proceedings of Impacts of Physics on the 

Frontiers of Medicine I. Lasers, Lake Buena Vista, Florida, Dec. 
8-10, 1986 

192. Constants of the Ss 1 ^, State of Na 2 , From Two-Photon Spectroscopy, 

(G.-Y. Yan, T.P. Duffey, W.-M. Du, andALS), J. Opt. Soc. Am. 
B4, 1829 (1987) 

193. Intracavity Absorption Detection of Magnetic-dipole Transitions in 

18 O 2 , and the determination of the b^*, (v=2) State Rotational 
Constants, (W.T. Hill III and ALS), J. Opt. Soc. Am. B5, 745 

194. Atoms, Molecules and Light, in Modern Physics in America: A 

Michelson-Morley Centennial symposium, William Fickinger and 
Kenneth Kowalski, eds . , American Institute of Physics AIP 
Conference Proceedings 169, American Institute of Physics, New 
York (1988), p. 26 

195. The Potential of the (S) 1 ^, State of Na 2 , by Two-Step Excitation 

Spectroscopy, (G.-Y. Yan, B.W. Sterling, and ALS), J. Opt. Soc. 
Am. B5, 2305 (1988) 

196. Doppler-free UV Excitation Spectra of C^-X'E*,, in Na 2 , by 

Modulated Population Spectroscopy, (G.-Y. Yan, B.W. Sterling, 
T. Kalka and ALS), J. Opt. Soc. Am. B6, 1975 (1989) 

197. Experimental Observation of the (3) 1 L U * State of Na 2 , by 

Deperturbation of the C 1 u -X 1 2' t g System, (G.-Y. Yan and ALS), 
J. Opt. Soc. Am. B6, 2309 (1989) 



198. First Observation of Perturbations on the C 1 ,, State of Na 2 , by CW 

UV Modulated Population Spectroscopy, (G.-Y. Yan, B.W. Sterling 
and ALS), Laser Spectroscopy IX, Proceedings of the Ninth 
International Conference on Laser Spectroscopy, M.S. Feld, J.E. 
Thomas, and A. Mooradian, eds . , Academic Press, New York, 
pp 402-404 (1989) 

199. Relaxation Oscillator Detection of Optogalvanic Spectra, (G.-Y. 

Yan, K.-I Fujii, and ALS) , Optics Letters 15, 142 (1990) 

200. A New Method for Detecting Optogalvanic Effect and Plasma 

Oscillation, (G.Y. Yan, K.-I. Fujii, and ALS), Proceedings 
of the Fourth International Conference on Laser Aided Plasma 
Diagnostics, Fukuoka, Japan, pp 415-420 (1989) 

201. Discovering Science (ALS) in A Voyage of Discovery: Messages from 

Nobel Laureates, Israel Halperin, editor 

201a. Discovering Science (ALS) in book for third world scientists, O.K. 
Nachtigall, editor 

202. Sharp Optical Lines in Rare Earth Barium Copper Oxides (D.W. 

Shortt, M.L. Jones and ALS) , Phys . Rev. B42,132 (1990) 

203. Felix Bloch (ALS) in Yearbook of American Philosophical Society 

1989, 174 (1990) 

204. Detection of Sharp Absorption Lines in Very Thin Nd 3 Films, (D.W. 

Shortt, M.L. Jones, A.L. Schawlow, R.M. Macfarlane and R.F.C. 
Farrow), J. Opt. Soc. Am. B8, 923 (1991) 

205. The Beginnings of Lasers, in Proceedings of Tropical Laser 90, 

International Laser Therapy Association, T. Ohshiro, Ed. (1990) 

206. Optical Line Spectra in Metallic (Nd, Ce) 2 ,Cu0 4 . x , (M.L. Jones, D.W. 

Shortt, B.W. Sterling, ALS and R.M. Macfarlane), submitted to 
Physical Review B (1991) 

207. Measurement of Diode Laser Characteristics Affecting Its Tunability 

with an External Grating, G.-Y. Yan and A.L. Schawlow, 
J. Opt. Soc. Am. B9, 2122 (1992) 

208. Laser, Licht und Materie, Naturwissenschaftliche Rundschau 

45, 211 (1992) 

209. Ultrasensitive Absorption Spectroscopy of Lanthanide Solids, (M.L. 

Jones, D.W. Shortt, B.W. Sterling and A.L.S.), submitted for 
Festschrift for Stanley S. Hanna (1992) 

210. Laser Technology for the Next Century, A.L. Schawlow in Proceedings of 

Laser Advanced Materials Processing, Nagaoka, Japan, June 8-12, 1992 
A. Matsuoka, editor 

211. Perspectives On Laser Spectroscopy, in Proceedings of Enrico Fermi 

Summer School, Varenna, Italy, June 29-July 10, 1992, Frontiers 
in Laser Spectroscopy, T.W. Hansch and M. Ingiusco, editors, North 
Holland (1994) page 1. 



212. Absorption Spectroscopic Measurement of Atomic Density in 

Laser-Induced Vapor Plume, T.P. Duffey, T.J. McNeela, J. Mazumder, 
and A.L.S., Appl . Phys . Lett. 63, 2339 (1993) 

213. Spectral Lineshapes for First-Surface Reflection from Solids, B.W. 

Sterling, A.L.S., and M. Jones, submitted to J.O.S.A. B, 1994 

214. Lasers in Perspective, A.L. Schawlow in Proceedings of the 

6th International Symposium on Advanced Nuclear Energy Research, 
Mito, Japan (Japan Atomic Energy Research Institute, 1995), page 3 

215. Fifty Years of Physics and Physicists, A.L. Schawlow, Physics in 

Canada, 1995 

216. Absorption spectroscopic measurements of plume density and temperature 

in production of nanocrystalline NbAl 3 by laser ablation 
deposition, T.P. Duffey, T.G. McNeela, T. Yamamoto, J. Mazumder and 
A.L. Schawlow, Phys. Rev. B, 14652 (1995) 











Paster autographed by the musicians, Hay 5, 194B 


Delta Jazz Band, Lansdoune Assembly Hall, December 2, 194B 

Ron Sullivan, Johnny Mitchell, F.L. Priestly, Bob Donnelly 
Art Schaujlotu, Jim Johnson, Barry Habberman, Ken Glandfield 





"The Jazz Band Ball" 

Lansdotune Assembly Hall 

Thursday, December 2, 194B 

B:45 - 9:15 pm 

Bob Donnelly 

Ron Sullivan 

Johnny nitchell 

Art Schaulouj 

Barrg Habberman 

F. L. Priestly 

Ken Glandfield 

Jim Johnson 









You've Gotta See Plama Ev'ry Night C vocal Donnelly 5 


Tin Roof Blues 

Darktouin Strutters' Ball 

Slow Blues 

Just A Closer Walk With Thee 






"The Jazz Band Ball" 

Lansdoiune Assembly Hall 

Thursday, December 2, 1348 

9:15 - 10:15 pm 

Frank tloujat 

Bud Hill 

Johnny Philips 

Clyde Clark 

Lyle Glover 

Harvey Hurlbut 

Jack Beattie 








Red Light Rag CthemeJ 

Cut It Loose CMy Bucket's Got A Hole In It) 

Working flan Blues 

I Thought I Heard Buddy Bolden Say 

Dallas Blues 

Squeeze He 

Ballin' The Jack 

Muskrat Ramble 

Tin Roof Blues 

Canal Street Blues 

Nobody Knows You When You're Down And Out 

Red Light Rag CthemeD 


C1D This tune was recorded, and sold as a ten-inch acetate record by Warner 
8 Herrifield Recording Service, Toronto. 


2. Live Appear? nces 

My first introduction to the Jazz fraternity in Toronto came on 
Thursday, tlarch 6, 1947, when the Jazz Society of Toronto held a concert of 
recorded Jazz, and invited the general public. They presented a 
well-balanced program of twenty-eight records covering the dixieland, New 
Orleans, blues, Chicago, and revival schools of Jazz. Although I had been 
collecting records for five years, the variety of styles came as a revelation 
to me. I can still remember sitting on those wood chairs before the meeting 
began, reading the handbill, and wondering what NQRK and QDJB meant! 

The Queen City Jazz Band, led by pianist Clyde Clark, was ths first 
amateur jazz band I ran across in Toronto. It had been playing for several 
years. In fact, at three private recording sessions in 1346, 1347, and 1348, 
they had recorded twelve sides which were issued as custom-made acetate 
records C2) . 

Ply first meeting with the band occurred at .a dance presented by Art 
Schatulow and the Jazz Society of Toronto on Hay 5, 1348. It was, for me, 
merely the first of many dances in various halls around Toronto, including 
Centre Island (a resort area offshore in Toronto harbour). 

ft memory comes back to me of one of these sessions - a warm summer 
evening, a refreshing breeze blowing in from the lake, an open-air dance 
floor called The Lido Deck on the main street of Centre Island, and up on tha 
bandstand the Queen City Jazz Band with all seven men playing their hearts 
out . 

I didn't dance at these sessions - I Just listened, spellbound, and 
wrote down the names of the musicians and the tune titles. When I returned 
home, I typed up the lists and filed them away. I did this for all the 
sessions described in this paper. So there's no faulty memory here; you can 
rely on the accuracy . 

The first time the band was recorded at a dance mas on July 21, 1348, 
when Art Schawlouj and Ulilf Goldstick set up a tape recorder and tried to 
record most of the music. ftfter the dance we all drove over to Uilf 's place 
to hear the results. ftlas, the tapes were unusable. It's a pity; I remember 
that the closing number, Canal Street Blues, was a long version, with time 
for a solo by each member of the band and each guest who was sitting in. 
Note that Bud Hill played string bass that night. When I expressed my 
surprise to Bud, he said, "Heck, any trombone player can play bass." 

In September of 1348 Ken Dean left the Queen City Jazz Band and formed 
his own band, Ken Dean's Hot Seven. Now there were two amateur bands to 
follow! For a teen-ager like me with a deepening appreciation of Jazz, that 
wasn't at all hard to take. The dance at the Todmorden Memorial Hall on 
August 13, 1948, was the first appearance of the band. 

In October, Bob Brimson played a dance at Coliton's fluto Livery with a 
sextet that I presume he put together for the occasion. He used four neiu 
members of the Queen City Jazz Band, plus Bud Hill's brother Ed on clarinet. 
The band played stock arrangements, interspersed with hot Jazz tunes. The 
singer, Jean Nesbitt, was Bob Brimson's girl friend. When she sang her 
dreamy vocals, two young bucks from the audience stood in front of her and 
swayed from side to side. Bob was ready to punch them out, but Jean felt 
they were sincere, and was flattered. I was sitting on the floor beside Bud 
Hill at one point and the arrangement must have been boring, because Bud 
leaned over to me and offered to let me blow his trombone part. I told him I 
hadn't a clue how to play trombone, but I don't think Bud would have minded. 



Edited by 

Behram Kursunoglu 

Arnold Perlmutter 

Center for Theoretical Studies 

University of Miami 

Coral Gables, Florida 




Arthur L. Schavlow 

Department of Physics 

Stanford University, Stanford, California 

In some vays , lasers seem to "be the realization 
of one of mankind's oldest dreams of technological pover 
Starting with the "burning glass, which was known to the 
ancient Greeks, it was natural to imagine an all- 
destroying ray of overpower ingly intense light. Francis 
Bacon, in his l62T New Atlantis , imagined that the in 
habitants of this Utopia had "all multiplication of 
light, which we carry to great distance, and make so 
sharp, as to discern small points and lines." In War of 
the Worlds. H.G. Wells' 1898 novel, Martians nearly 
conquered the earth with a sword of light. In 1923, the 
Russian novelist Alexei Tolstoi wrote The Hyperboloid of 
Engineer Garin. Then, in the 1930's the Buck Rogers 
comic strip often made use of a disintegrator gun. 

Yet many old dreams, which have more or less come 
true in this century, are realized only more or less. 
Men dreamed of flying like birds and now they do fly, 
but it is not at all like birds. Similarly, most lasers 
deliver far less than the destructive death rays of 
science fiction but their light has properties, such as 
monochromaticity and coherence, which go far beyond the 
old dreams . 

Rays of any kind were far from the minds of Charles 
H. Townes and myself when, in 1957, we began to think 
seriously about the possibility of optical masers . 
Rather, we were thinking of what was already a classic 
problem in pure technology: to find something which 



vould act like a radio tube and generate shorter radio 
waves. "Daedalus" has pointed out in New Scientist 
(December 22, 1965) that there is a body of research 
vhich seeks to find ways to do things for their own 
sake. There may well be no immediate application in 
sight, but such pure technology "like pure science, 
often has to masquerade as the applied variety in order 
to get funds." Some problems in pure technology may 
appear as frivolous as "the development of a square 
gramophone record played with such a perfect quadri 
lateral-linear motion that corner effects are imper 
ceptible." But others play a serious part in the 
development of technology. Even though their appli 
cations are not immediately foreseeable, they do parallel 
or extend lines of enquiry which have been fruitful in 
the past . 

Throughout the twentieth century, scientists and 
engineers have sought to extend radio techniques to 
shorter wavelengths. As a boy in the 1930's I had read 
in the Radio Amateur's Handbook that after World War I, 
the amateurs "couldn't go up [in wavelength], but we 
could go down. What about those wavelengths below 200 
meters? The engineering world said they were worthless 
--but then, they'd said that about 200 meters, too." 
After preliminary tests and "some months of careful 
preparation, two way amateur communication across the 
Atlantic finally became an actuality when Schnell, 1MO, 
and Reinarty, IXAM , worked for several hours with 8AB, 
Deloy in France, all three stations using a wavelength 
of about 110 meters." Still shorter waves, with lengths 
ranging from 10 to 80 meters, were found to make possible 
world-wide communications. 

In the 1930's, amateurs and others found ways to 
use very high frequency waves whose lengths were shorter 
than about ten meters. These waves did not travel 
much more than line-of-sight-distances , but they were 
found to be suitable for reliable, broad-band broad 
casting such as for television or stereo music. With 
inventions like klystrons and cavity magnetrons it be 
came possible to explore the properties of waves of 
centimeter lengths. These waves were not suitable for 
"broadcasting since they could be stopped by almost any 
obstacle. However, their short wavelength made them 
useful for high-definition radar and for relaying broad 
band communications. 

From all this, it seemed overwhelmingly probable 



if some way could be found to generate shorter wave 
lengths, there would be uses for them. Some of the 
uses would be obvious, like communications, but there 
was a good chance that the unforeseen uses would be even 
more exciting. There were, of course, ways of producing 
shorter electromagnetic waves from many kinds of hot 
bodies. Such sources, like the sun and electric lamps, 
could be quite bright, but they lacked several of the 
desirable properties of electronic oscillators. The 
output was always a rather broad band of frequencies. 
Since the excited atoms or molecules radiated spontane 
ously and independently of each other, their output did 
not have spatial coherence. Moreover in the infrared, 
and especially for the longer infrared wavelengths, 
spontaneous emission was relatively slow so that the 
power emitted was small. 

One of the requirements for building an electronic 
oscillator to generate such short electromagnetic waves 
is the resonators to tune it. For microwaves, which 
have lengths ranging from millimeters to centimeters, 
tuning is usually achieved with some kind of cavity 
resonator whose dimensions are comparable to the wave 
length. When the desired wavelengths are a small 
fraction of a millimeter, construction of cavity reso 
nators becomes a very difficult task. But nature has 
provided us with many kinds of atoms and molecules with 
natural resonances throughout the infrared and optical 
wavelength regions. Even when I was an undergraduate 
student, in the late 1930's, it seemed to me- that there 
ought to be some way to use these in amplifiers or 
generators of infrared waves. But I did not know 
enough quantum physics to even begin trying to find a 
way to do it. Very likely others had similar vague 
ideas and, indeed, the formal similarity between atomic 
absorptions and resonances of tuned circuits had long 
been recognized. 

The connection between radio waves and atoms was 
again emphasized by the growth of radiof requency and 
microwave spectroscopy in the years after World War II. 
I was then a graduate student at the University of 
Toronto, having interrupted my studies for war work 
teaching at the University and then microwave antenna 
engineering in a radar factory. At the University of 
Toronto, we did not have the facilities for the 
glamorous fields like nuclear physics and radiof requency 
resonances. So, I was happy to work, under Professor 
Malcolm F. Crawford, on hyperfine structure in the 



spectra of atoms. With another graduate student, 
Frederick M. Kelly, I constructed an atomic "beam light 
source to give spectral lines sharp enough so that 
their hyperfine structure could "be analyzed. Another 
graduate student, William M. Gray, constructed a spectro- 
graph and a Fabry-Perot interferometer to use with our 
source. Thus I became highly familiar with this inter 
ferometer, consisting of two parallel, partially- 
transmitting mirrors facing each other. This instrument 
had been studied in undergraduate optics classes, but 
even though most of the work with the interferometer 
was done by the others in our group, I did learn more 
about it during our research. When I began to think of 
resonators for light waves a decade later it seemed 
natural to start with the Fabry-Perot structure of two 
mirrors facing each other. 

In the postwar years, it seemed to me that the 
most exciting physics research was at Columbia University 
I.I. Rabi was still active, and W. Lamb and P. Kusch had 
recently made discoveries which were immediately re 
cognized as important and later brought them Nobel 
Prizes. I wrote to Rabi, and he suggested that I apply 
for a postdoctoral fellowship to work with Associate 
Professor C.H. Townes. This fellowship was provided by 
the Carbide and Carbon Chemicals Corporation, a division 
of Union Carbide, to support research on the application: 
of microwave spectroscopy to organic chemistry. I had 
neither knowledge of nor interest in organic chemistry, 
but microwave spectroscopy was an attractive new field. 
I must also confess that I had not heard of Charles 
Townes, although I soon found that he had recently 
published a number of discoveries. At any rate, I 
applied for and was awarded the fellowship. 

After coming to Columbia University, I learned that 
although microwave spectroscopy can be use-d to determine 
the structure of organic molecules and for analysis, 
that was not the only reason for Carbide and Carbon 
Chemicals' sponsorship. As early as August, 19^5, Dr. 
H.W. Schulz, a member of their research staff, had 
written a memorandum to propose a new type of catalysis 
"to employ electromagnetic radiation of a specific fre 
quency to effect activation of reacting molecules by 
induced resonance." In this memorandum he stated that 
"The pertinent frequency range would cover the long and 
short wave radio bands as well as the infrared, visible 
and ultra-violet spectra. A literature search indicates 
that this principle has previously been employed only in 



the case of photocatalysis . " As his study proceeded, 
Dr. Schulz came to realize that resonance catalysis 
would need the tunability and power of radio generators, 
"but at a shorter wavelength than was available from 
existing oscillators. After various alternatives were 
considered, it was decided to support long range research 
aimed in this general direction at a major university. 

At Columbia University, there was a Radiation 
Laboratory group in the physics department, continuing 
a program from the wartime days on magnetrons to 
generate millimeter length radio waves. Also there was 
Townes, who had recently come from Bell Telephone 
Laboratories and was making pioneering studies of the 
interaction between microwaves and molecules. The 
laboratory was supported by a Joint Services contract 
from the U.S. Army, Navy and Air Force, with the general 
aim of exploring the microwave region of the spectrum 
and extending it to shorter wavelengths. Dr. Harold 
Zahl of the Army Signal Corps and Paul S. Johnson of the 
Air Force Office of Scientific Research were among those 
active in the sponsorship of this program. Captain 
Johnson also organized a millimeter wave study committee 
and asked Townes to be its chairman. As Townes has 
recounted, it was on the morning of a meeting of this 
committee that he conceived the idea of the maser. 

Thus during my stay at Columbia there was wide 
spread recognition that it was interesting to find 
better ways to generate wavelengths shorter than those 
produced by existing electronic devices. But nobody 
had a good idea of how to do it, and so Townes 1 group 
concentrated on exploring the structures of molecules 
and their interaction with microwave radiation. This 
turned out to be the right decision, for a detailed 
understanding of the ammonia molecules was Just what 
Townes needed to invent the maser in the Spring of 1951. 
In this ammonia maser, a beam of ammonia molecules 
would pass through a suitable electric field which would 
accept those in excited states and reject the unexcited, 
absorbing molecules. The excited molecules could be 
stimulated to emit microwave radiation inside a cavity 
resonator, a metal box having dimensions comparable 
with the wavelength. 

Townes told me about his idea in May or June of 
1951, and it seemed promising. I would have liked to 
work on it, but my time at Columbia University was coming 
to an end and I had accepted a Job in solid state physics 



at Bell Telephone Laboratories. 

My vork took me quite far away from problems of 
generating electromagnetic radiation. I kept in touch 
with Townes, "because we were writing a book on Micro 
wave Spectroscopy and I spent nearly every Saturday at 
Columbia University. Thus I heard from time to time 
about the problems and progress of the work on the 
maser and was delighted when it first operated in 195^. 
At about that time, interest in masers began to pick up 
at Bell Telephone Laboratories and two years later, G. 
Feher, H.E.D. Scovil and H. Seidel built the first 
three-level solid state microwave maser following a 
proposal by Nicolaas Bloembergen of Harvard University. 
While the original ammonia maser had been primarily 
useful as a frequency standard or as a sensitive 
detector for studies of the ammonia molecules, the 
solid state maser was something that could actually be 
used for communications and radar. It had a broader 
band width and could be tuned by changing the strength 
of a magnetic field. Not long afterwards, C. Kikuchi 
of the University of Michigan showed that ruby was a 
good material for such masers. Joseph Geusic, who came 
to Bell Labs from Ohio State University about that time, 
where he had done his thesis with J.G. Daunt and had 
for the first time measured the mivrowave resonances in 
ruby, was one of those who became active in designing 
and perfecting ruby masers. 

I did not participate in any of this except as a 
spectator, being busy with research on superconductivity 
and, for a time, nuclear quadrupole resonance. I also 
taught twice a three month course in solid state physics 
for the engineers in the program which Bell Laboratories 
had established for new engineers coming from college 
with Bachelor's or Master's degrees. 

When parametric amplifiers were rediscovered by 
Harry Suhl, we thought perhaps this might somehow be a 
clue to producing shorter wavelengths and I spent a 
little time learning about them. I even built an audio 
frequency parametric amplifier too. It may well have 
been the first one at Bell Labs since the work of 
Peterson some years earlier, which had by then been 
nearly forgotten and was not known to me. 

By 1957, I was coming to think that the time was 
right for a serious investigation as to whether one 
could build some kind of an infrared maser. Naturally, 



I was thinking primarily about the wavelength region 
just a little shorter than could be obtained by radio 
tubes. Townes had hoped initially that his ammonia 
maser would oscillate at a wavelength of a half milli 
meter, but in the final device the output was at one 
and a quarter centimeters wavelength, which is well 
within the region spanned by existing microwave tubes. 
I remember attending a conference on low temperature 
physics at the University of Wisconsin in August 1957 
and chatting there with Michael Tinkham, who was then 
at the University of California and had been doing some 
far-infrared spectres copy . This kind of spectroscopy 
was very difficult, because the existing light sources 
were extremely weak and so I suggested that it really 
ought to be possible to build some kind of a maser to 
produce a stronger source. Tinkham mentioned that iron 
in crystals had energy levels in a right wavelength 
region, but neither of us did anything more about it at 
that time . 

A few weeks later, about October of 1957, Charles 
Townes visited Bell Labs and we had lunch. Townes had 
been consulting with the Laboratories for about a year, 
but his contacts were with the maser people and I had 
not had any serious discussions with him. He told me 
then that he was interested in trying to see whether an 
infrared or optical maser could be constructed, and he 
thought it might be possible to Jump over the far infra 
red region and go to the near infrared or perhaps even 
visible portion of the spectrum. He had made some notes 
and said that he would give me a copy. We agreed that 
it might be worthwhile for us to collaborate on this 
study and so we began. 

We both realized that the three-level and four- 
level pumping schemes, used in microwave masers, could 
be used with incoherent light as a pump if we could get 
enough power from the incoherent light. Indeed, Townes 
had envisioned optical pumping of masers as early as 
195^, and had mentioned the method in his basic maser 
patent. Just as in the microwave maser the ammonia 
molecules are excited independently and enter the 
resonator quite individually, so we could excite in 
dividual atoms or molecules in any kind of a maser at 
random. The synchronization would be achieved by a 
wave stored in a resonator. 

However, excited atoms lose their stored energy 
even if they are not stimulated. In solids at 



radiofrequencies the energy is lost "by transfer to the 
crystal vibrations where it "becomes heat, "but in the 
visible region spontaneous radiation may be more impor 
tant. It was not at all obvious whether one could get 
enough excited atoms despite spontaneous emission, and 
the only way to answer this question seemed to be to 
study the properties of some fairly simple substances 
which might be calculable. Although solids and liquids 
are known to emit strongly, gases are simpler and better 
understood and the simplest gases are those consisting 
of individual atoms. Townes thought he saw a suitable 
system in thallium vapor and had described it in the 
notes he gave me. 

The thallium atoms would be excited from the 
ground state (6p) to a higher one (either 6d or 8s) by 
ultraviolet light from a thallium lamp. Such lamps 
were in use in Kusch's laboratory at Columbia University 
for experiments on optical excitation of thallium atoms 
in an atomic beam resonance experiment. Townes had dis 
cussed with Gordon Gould, a student of Kusch's who was 
working on the atomic beam experiment, the properties 
of thallium lamps to find out how much power could be 
expected from them. Atoms excited to the 6d or 8s 
level would, according to Townes 1 scheme, rapidly 
radiate part of their stored energy and drop to the Tp 
level which would be the upper level for maser action. 
From there they could be stimulated to make transitions 
to a 7s level which would normally be empty. 

After looking at this, I saw a flaw in it, in that 
the rate of spontaneous transition was greater out of 
the 7s to the 6p than from the 6d or 8s into the 7p" 
This means that the 7p state, which was to hold atoms 
to be stimulated, would empty faster than it filled. 
Laser action might not be impossible under those circum 
stances, but it would be difficult, and it pointed out 
a general problem with this sort of a cascade operation 
in atoms. It is rather usual, although there are ex 
ceptions, that the various excited states have progres 
sively longer lifetimes as you go up except for the 
ground state whose lifetime is essentially infinite. 

However, if Townes' thallium scheme was not 
immediately workable it did make an important point. 
It would be easier to do a theoretical analysis for 
transitions of a maser to emit radiation in or near the 
visible than it would be for the submillimet er region, 
where so little was known experimentally. It might ever 



be that it would "be actually easier to "build one in the 
near-visible region because the spacings between energy 
levels in that region are large enough so that thermal 
excitations do not quench excited atoms as quickly as 
they do for levels with the smaller spacings corre 
sponding to the far infrared. So, we searched for suit 
able energy levels and transitions in some atoms which 
might be excited to emit radiation in this portion of 
the spectr um . 

In this quest, we had a good deal of information to 
guide us, although not all the questions we wanted had 
been asked. The energy levels of many atoms were tabu 
lated in the volumes prepared by Charlotte Moore of the 
National Bureau of Standards. Some transition proba 
bilities were given in the Landolt-BBrnst ein Tables, in 
a Table edited by L. Biermann. These would give us a 
start and would give references to more complete in 
formation in original papers. 

How many excited atoms would we need? Townes had 
the maser equation which he modified by letting sponta 
neous emission loss replace the other kinds of losses 
which had been dominant for microwave masers. The equa 
tions are given in the paper which we published in 1958, 
but essentially what he did was to imagine light waves 
traveling in a box which could be thought of, for the 
derivation, as a rectangular box with reflecting walls. 
Light would be lost only at the walls, and, knowing that 
light waves travel at the velocity of light, one could 
easily calculate the average time between wall reflec 
tions. Then from that you could get the ratio of energy 
lost to energy stored for an electromagnetic wave in the 
box, provided you know the reflection loss each time the 
wave reaches a wall. The rate of stimulated emission of 
energy from the excited atoms depends on the intensity 
of the stored wave, as do the losses. One needs then to 
calculate how many excited atoms are needed to overcome 
the losses. Now the excited atoms will radiate in a 
short time which might range anywhere from billionths of 
a second to perhaps thousands of a second and must be 
replaced on the average once each lifetime. Thus we can 
calculate the number of excited atoms neoded per second 
to just make up the losses in this resonator. If we had 
more than that we can increase the losses by' opening the 
hole or making the walls partly reflecting so that we 
can take out some of the energy generated. 

In the microwave regions, the strength of the 



interaction of the molecules with the stored electro 
magnetic wave is visually measured "by the dipole moment 
of the molecule. One can give an effective dipole 
moment for an optically excited atom, but it is more 
usual to use the quantity known as the oscillator 
strength, f, which is related to the dipole moment. 
This is the quantity most commonly tabulated in places 
such as the Landolt-Bo'rnstein Tables and more extensive 
compilations which have appeared since then. The 
oscillator strength, f, indicates the effective number 
of electrons available for the particular atomic res 
onances and may range from one down to a very small 
fraction of one, or in a few exceptional cases it can be 
greater than one but not commonly. It can be measured, 
for example, if you know how many atoms there are in the 
ground state by determining the strength of the ab 
sorption of light within the band which the atom can 
absorb. Measurement for excited state is more diffi 
cult because it is not easy to know just how many atoms 
there are in each of the excited states but some measure 
ments have been made. 

Probability of stimulation by a given wave is 
proportional to oscillator strength, and so also is the 
gain for a given number of excited atoms. Thus to get 
a large gain without exciting very many atoms, we would 
wish to have a large oscillator strength. However, since 
the oscillator strength measures the interaction be 
tween the atom and an electromagnetic wave, the rate of 
spontaneous emission is also proportional to the oscil 
lator strength. That is, the greater the oscillator 
strength the shorter the lifetime of the excited state 
and the faster we have to replace the excited atoms. It 
turned out, then, that it did not really matter what 
the oscillator strength was for the particular transi 
tion. If it was high, we would need only a few atoms 
but we would have to replace them frequently. If it 
was low, we would need many atoms, but would not have 
to replace them as often. Thus the oscillator strength 
would not matter at all, if atoms lost their excitation 
only by emitting the desired radiation. But if there 
are competing processes, it is helpful if the desired 
one has a large oscillator strength. 

Another factor, important for the gain of a 
particular atomic resonance, is the width of the spec 
tral line. The probability of stimulated emission, 
and hence the gain from a given number of excited atoms 
is inversely proportional to the width of the spectral 



line. Fortunately, for a gas at low pressure, the 
linewidth is known to "be given "by the Doppler effect 
from the thermal motions of the atoms. This is easily 
calculable. In solids and liquids the linewidths are 
much more variable. When, later, we "began to think 
seriously about these materials, we had to make our own 
measurements of linewidths. 

We concentrated our study on the simplest atoms, 
the alkali metals. While the hydrogen atom's spectrum 
is perhaps even simpler and more theoretically calcul 
able, hydrogen exists in the form of molecules which 
have to be disassociated and the efficiency of the 
dissociation would introduce additional uncertainty. The 
alkalis have only one electron outside a closed shell 
and so can be thought of as nearly one-electron atoms. 
Their energy levels are well known and the metals are 
not hard to vaporize. Moreover, alkali vapor lamps are 
commercially available by a number of companies and in 
deed sodium vapor has been widely used for street light 
ing. I chose to look most carefully at potassium for a 
rather trivial reason. Both the first and second members 
of the principal series of potassium vapor lie in the 
visible region. That is, one could pump potassium atoms 
from the ground Us state up to the 6p with visible 
UoUTA light from a potassium vapor lamp and then monitor 
the progress of these atoms back to the ground state by 
looking at the red line emitted when atoms drop from the 
5p to the Us state. In the other alkalis, one or the 
other of these transitions lies in the infrared or 
ultraviolet. These are obviously not very important 
considerations, but I had essentially no optical 
equipment at all at the time and was thinking whether 
one could begin experiments easily and cheaply. More 
over, it did seem that any conclusions from one atom 
would be pretty much applicable to the others. 

I bought some commercial Osram alkali vapor lamps 
and one of my colleagues, Robert J. Collins, measured 
the power output of some of these lamps for me. Collins 
had done his thesis research in spectroscopy and was by 
that time a Bell Laboratories physicist working on some 
infrared spect ros copic studies. He found that each of 
the lamps generated to 0.08 milliwatts in the kOhlR line. 
Of course this was only one small lamp and was not 
designed for maximum power. One could imagine buying 
large arrays of such lamps or, if necessary, building 
them. But the 0.08 milliwatts, if we could use all of 
it, would be sufficient to excite quite a large number 



of atoms in a potassium vapor cell. So as our calcu 
lations progressed, vith the aid of tables of measured 
oscillator strengths published years "before, it "began to 
look that you could indeed get enough excited atoms to 
obtain measurable amplification in the excited state. 

During this time ve had not been paying too much 
attention to the resonator vhich we would need to 
complete the maser oscillator. I had in mind from the 
beginning something like the Fabry-Perot interferometer 
I had used in my thesis studies. I realized, without 
ever having looked very carefully at the theory of this 
interferometer, that it was a sort of resonator in that 
it would transmit some wavelengths and reject others. 
Such an interferometer might typically have had mirrors 
with diameters of perhaps 7 cm and spacing of perhaps 
that much or less. Somehow it must have been implicit 
in our thinking that the absence of the side walls did 
not really matter too much. However, as we began to 
feel satisfied that it was possible to get sufficient 
excitation our attention turned more toward the properties 
of the resonator. The number of modes of oscillation 
of such a resonator, having dimensions tens of thousands 
of times larger than the wavelength, was enormous even 
in the limited range of frequencies which the atoms 
could amplify. 

All physicists learn how to calculate the number of 
modes of waves in a large volume somewhere around the 
end of undergraduate or the beginning of graduate studies. 
This kind of calculation is important, for example, for 
estimating the spontaneous emission lifetime of excited 
atoms and for the derivation of the well known law for 
the intensity for emission from a heated black body. 
The same kind of counting up of modes is used in the 
Debye theory of specific heat, where the thermal motions 
of the atoms in a solid are considered to be entirely 
equivalent to a superposition of all possible random 
thermal waves of wavelengths from very long ones to those 
whose wavelength is Just twice the spacing between the 
atoms. I have been through this as an undergraduate, 
but my memory had been particularly refreshed when I 
taught the Debye theory of specific heat to the en 
gineers at Bell Telephone Laboratories. However, at 
first I simply looked at the number of modes and then 
began to think what the output of the optical maser 
might be like if we had one. 

Martin Peter, another colleague at Bell Laboratories, 



vas particularly insistent that ve should find some way 
to reduce this enormous number of possible modes. Other- 
vise, he felt the optical maser, if it did oscillate, 
vould jump rapidly from one mode to the other and not 
produce any very recognizable kind of oscillations. 
The coherence of the radiation vould be continually 
interrupted by jumps from one mode to a different one. 
Tovnes had recognized the importance of this multimode 
problem, and it had kept him for a long time from 
proceeding vith short-vave masers. When ve began our 
vork together, he believed both that it vas important 
to damp out other modes and assure that there vas good 
mode control, but that even though he could see no 
system vhich vould do this completely, one should go 
ahead in any case, thinning out the modes as much as 
ideas vould permit. He expected that the oscillator 
vould oscillate momentarily on a single or a limited set 
of modes because of nonlinear it ies , but that it vould 
also jump fairly rapidly betveen different modes. He 
believed that one could easily determine that the system 
had gone unstable and vas vorking, and that the propertie 
even vith a complex set of modes vould be recognizable 
and interesting. Very possibly, if Tovnes and Peter had 
discussed the question directly, they vould have reached 
some sort of agreement. None of us doubted that some 
good method of mode selection vas highly desirable. 

I began to think of these modes in terms of the 
vaves of the Debye picture, that is vaves traveling in 
different directions inside the resonator and having 
different vavelengths. The range of vavelengths vas 
limited by the bandvidth of the amplifying atoms. Nov, 
to reduce the number of directions that vould be accept-' 
able in the instrument vas not so easy. I thought for 
avhile that perhaps there might be certain directions 
in vhich the light could come out of the box, as there 
is in a Fabry-Perot resonator, and that the output might 
be an array of beams like the Laue spots of the x-ray 
diffraction camera. I thought at one time of replacing 
the vails of the box by diffraction gratings ruled so 
that they vould only reflect light veil for a particular 
angle of incidence and that only vaves coming in this 
right direction vould be properly reflected. 

Having advanced this far, around the beginning of 
February 1958 I vrote dovn my ideas about optical masers 
in my notebook. Of course many very vise scientists 
vill tell you that any scientist vorth his salt care 
fully records all observations, calculations and concepts 



in his laboratory notebook. However, I fear that I do 
not qualify, because in seven years at Bell Telephone 
I had not yet filled one notebook. Indeed my ex 
perience had been that the only valuable calculations 
and data were those that I took on scraps of paper. 
Whenever I thought I had things in sufficiently good 
order to record them in the notebook it turned out that 
I had overlooked something and that that particular work 
was essentially worthless. However, I did write down a 
number of pages of thoughts about optical masers. They 
included some calculations on potassium and the re 
ordering of the equations and some of the ideas about 
possible structures, even though I was not at all con 
fident that the problem of mode selection was solved. 
Even though I had never tried to patent anything, I 
asked Solomon L. Miller to read and witness these notes, 
on January 29, 1958. Miller had been one of Townes ' 
graduate students when I was at Columbia University and 
had a laboratory near mine at Bell Telephone Labora 
tories. He was certainly well able to understand the 
discussion in my notes and so indicated when he signed 
them. I was a bit startled, Just a few days later, to 
learn that Miller had left Bell Labs to go to IBM. 
Perhaps that had something to do with my never writing 
any more ideas in my notebook. 

But indeed I did get a good idea very soon after 
writing these notes. I realized that if we took liter 
ally the Debye picture in which the various modes were 
waves having different lengths going in different di 
rections, it could suggest a way to select one, or at 
most a few of these modes. If a wave started from some 
where near one wall of the resonator, it would reach a 
different place on the far wall, depending on its di 
rection. If, therefore, most of the far wall were 
eliminated so that only a small patch remained, the wave 
would only be reflected if it were going in the right 
direction to reach that small patch of wall. 

Thus we could reduce the large box to just two 
small mirrors facing each other at the ends of a long 
column of excited atoms. This arrangement would serve 
as a good resonator for waves which travel nearly 
straight along the axis Joining the mirrors. A wave 
with any other direction would soon move sideways enough 
to miss the small end mirror, and thus would be lost. 

It was clear to me then that this resonator could 
not hold any wave unless its direction of propagation 



vas inclined to the axis by less than the angle sub 
tended by one mirror at the position of the other. 
Townes pointed out that this structure would be con 
siderably more selective than that. Waves were expected 
to bounce many times back and forth through the amplify 
ing medium. Only a wave traveling quite exactly along 
the axis would remain in the amplifying medium long 
enough to attain a high intensity by stimulating emission. 

This simple reasoning convinced us that we had 
found a structure which would really strongly favor the 
growth of a few selected modes. It was also apparent 
that the output through one of the partially-reflecting 
mirrors would be a highly directed beam, more or less 
approximating a plane wave. We were also satisfied that 
we kaew of at least one substance in which we would be 
able to excite enough atoms for optical maser action. 
However, it would take an uncertain time to build one, 
and unexpected experimental problems might well be en 
countered. We were aware that, during the three years 
which it took to construct the ammonia maser, some of 
the ideas had been discovered and published by others. 
There were many more workers in the field by 1958. Al 
though we were not aware of any direct competition and 
did not particularly try to hurry, it seemed best to 
publish our conclusions without waiting for experimental 
verification. During the spring months we worked most 
ly on writing the manuscript. 

Before submitting the paper for publication, we 
were required to circulate the manuscript to our 
colleagues at Bell Telephone Laboratories for technical 
comments and to the patent department to see if it in 
volved a patentable invention. Several people, parti 
cularly some of those most expert in microwave waveguide 
theory, were skeptical of the reality of our modes and 
the proposed method of mode selection. They wanted to 
see a more complete calculation with rather precisely 
defined boundary conditions, which was done only later, 
in I960, by A.G. Fox and T. Li. We did, however, add 
some paragraphs to our paper, in the hope of making the 
mode frequency and selection argument more complete and 
clear. There was some worry that there might be some 
modes of the resonator with longitudinal field components, 
as are found in microwave resonators. However, in a 
resonator like ours, the wave travels many thousands of 
wavelengths from one mirror to the other, and must be 
have much like a wave in free space, and so must be 
largely a transverse wave. 



The patent department was, at first, quite un 
interested in the idea. I suppose that it appeared to 
be remote from the needs of the telephone industry and 
perhaps they did not believe it would work or that if 
it did it would be very useful. However, largely at ^ 
Townes 1 insistence they did prepare and file an appli 
cation for a patent. It was issued rather speedily, in 
March, I960. Our paper was submitted for publication, 
in August of 1958, and was published in the Physical 
Review in the December 15 issue of that year. 

The paper did arouse a considerable amount of^ 
interest and a number of laboratories began searching 
for possible materials and methods for optical masers. 
Townes, in his own group at Columbia, began efforts to 
construct a potassium optical maser, working particular 
ly through two graduate students Herman Z. Cummins and 
later Isaac Abella. They were Joined for a time by 
Dr. Oliver S. Heavens who is now Professor of Physics 
at York University in York, England and who was even 
then a world renowned expert on highly reflecting 
mirrors . 

We were of course aware of other possible materials 
for optical masers. One of these was cesium vapor. 
Cesium had the additional advantage that it could be 
pumped by a strong spectral line from a helium lamp, 
which happened to coincide with one of the cesium atom's 
absorption wavelengths. This coincidence had been 
noted in 1930 by C. Boeckner and mentioned in A.C.G. 
Mitchell and M.W. Zemansky's book Resonance Radiation 
and Excited Atoms (Cambridge University Press, 193 1 *) 
We noted in our paper that a cesium infrared maser could 
thus be pumped by a helium lamp. This kind of a laser 
was constructed and successfully operated by S. Jacobs, 
G. Gould, and P. Rabinowitz in 196l . Thus by 1958 we 
knew a number of gases suitable for optical maser action, 
although we could not be sure which would be easiest. 

Being at Bell Laboratories, I had been pretty 
thoroughly indoctrinated to believe that anything that 
you can do in a gas can be done in a solid and can be 
done better in a solid. I therefore began to explore 
the possibility of solid optical maser materials. 
Albert Clogston, who was my immediate boss at Bell 
Laboratories, had encouraged my interest in optical 
masers and now encouraged me to, if I wished, drop super 
conductivity entirely and begin studies of possible 
optical maser materials. On the other hand, nobody ever 


suggested that we try and organize a group to build an 
optical maser. Anything I did I would have to do my 
self. There was a nearly invariable custom in the 
physical research department that each man was to be an 
individual scientist, and not an assistant to anyone 
else . 

About the optical properties of solids, indeed my 
ignorance was quite total. However, even before our 
paper was published I began to learn a little bit. One 
thing that impressed me was that some materials such as 
ruby had broad absorption bands and narrow emission 
lines. Thus we were able to say in our 1958 paper that 
"The problem of populating the upper state does not have 
as obvious a solution in the solid case as in the gas. 
Lamps do not exist which give Just the right radiation 
for pumping. However, there may be even more elegant 
solutions. Thus it may be feasible to pump to a state 
above one which is metastable. Atoms will then decay 
to the metastable state (possibly by nonradiative proc 
esses involving the crystal lattice) and accumulate 
until there are enough for maser action. This kind of 
accumulation is most likely to occur when there is a 
substantial empty gap below the excited level." 

When writing that, ruby seemed like a tantalizing 
possibility because it did glow so brightly almost no 
matter how you excited it. Several people about that 
time had become interested in the optical emission from 
ruby including Saturo Sugano and Y. Tanabe and their 
associates in Japan, Irwin Wieder at the Westinghouse 
Research Laboratories, and Stanley Geschwind at Bell 
Laboratories. But ruby seemed also to present a very 
serious difficulty. The transition for the only strong 
fluorescence lines were absorbed by unexcited atoms in 
the same material. That is, they were resonance lines 
and so the atoms could both absorb and emit the same 
wavelength. Thus one would start out with the dis 
advantage that initially all the atoms would be ab 
sorbing, so that half of them would have to be excited 
before any amplification at all could be obtained. With 
out doing any calculations this really seemed like too 
much of an obstacle to overcome, although there might be 
some way because of the broad absorption bands for 
pumping. Several people made measurements on the 
fluorescence efficiency and strangely enough they all 
gave estimates ranging from 1 to 10 percent. I now 
think they were all trying to be conservative, but if 
we had done a calculation and believed their figures we 



would have confirmed our prejudice that it was not 
possible to obtain optical maser action in the resonance 
lines of ruby. But I thought that perhaps there might 
yet be some way, such as by splitting the energy levels 
in a large magnetic field so that one sublevel at least 
would be empty at low temperatures. 

How was it that so many people at nearly the same 
time began to study the optical properties of ruby? 
Well, the one reason was that there had been an advance 
in the understanding of crystals related to paramagnetic 
resonance studies which could carry over into the optical 
spectra. The dominant influence in my case and perhaps 
in some others, was that ruby was being used in micro 
wave masers. It was possible to visit Joe Geusic or 
others at Bell Labs and find a drawer full of rubies 
from which you could easily borrow samples. So much was 
my practice to borrow samples that I remember a year or 
so later that George Devlin marked on one of the spectra 
"ruby ALS bought!," because up to then I had been most 
ly borrowing . 

One advantage of all this interest in ruby was that 
crystals had been ordered and were available and with 
various concentrations of chromium in aluminum oxide. 
Although I did not think that ruby was going to be any 
use for an optical maser material, it was interesting 
because it seemed to have a fairly simp" :pectrum, 
which according to the theory should ha .:ad Just two 
emission lines at low temperature along t.h some bands. 
Indeed at the very lowest temperatures it should have 
only one emission line. In actual fact, as had been 
shown many years ago by a number of experiments and most 
thoroughly by Otto Deutschbein in 1932 and by S.F. 
Jacobs and G.H. Dieke in 1956, there were very many 
lines in the spectrum of ruby. I thought naively that 
these extra lines might be due to the int'eraction of the 
chromium ion with the crystal lattice vibrations and 
that if we studied them it would give us some information 
about the crystals. It also seemed interesting to look 
at the c'rromium spectrum not only in aluminum oxide but 
in the related gallium oxide which Joe Bemeika could 
grow as small crystals with various concentrations. 

I had at that time a Gaertner wavelength spectro 
meter, a very simple student-type instrument which I 
had bought when I first went to Bell Labs thinking that 
it could be used for measuring thickness of thin metal 
films. Darwin Wood was in charge of spectrochemi cal 



analysis and he could make available some time on his 
spectrographs and indeed collaborated with us on some 
of our early studies. 

I have mentioned George Devlin, who vas my tech 
nician during most of my years at Bell Labs. I had 
hired him even though he had very little formal train 
ing and really a rather poor high school education. He 
had, however, been a champion model airplane builder 
and it was evident that he had an attractive personality 
and a quick mind. It turned out to be a very rewarding 
association. For Devlin, although he was almost complete 
ly nonmathematical , had a real physical insight as well 
as skill in designing, building and operating -equipment . 
Perhaps one of his most valuable characteristics, was 
that he did not have any great preconceptions as to what 
the data should be. Several times, he pointed out to me 
small effects which I would have dismissed as noise but 
which he insisted were real and turned out to be inter 
esting. One of these was that when we were looking at 
various samples of gallium oxide crystals with various 
concentrations of chromium, he noticed that the satel 
lite lines, that is the extra lines to the red of the 
strong R-line, were different in different samples. That 
was all I needed and I immediately Jumped to the- con 
clusion that these lines were not due to the crystal 
vibrations but rather to pairs of chromium ions. The 
probability of a given ion having a near neighbor in a 
particular crystal ion position was going to be propor 
tional to the concentration of the ions in the crystal. 
At low concentrations such close neighbors would be 
very unusual and at high concentrations they would be 
common. This of course would also be the explanation 
for the extra lines in ruby. Darwin Wood and I in 
vestigated this point more quantitatively, collaborating 
with Albert Clogston on the theoretical aspects, and we 
published a note on the pair spectra in the summer of 

However, one of the most interesting features of 
this pair spectrum was that it could produce a large 
splitting in the ground state of the chromium ions 
which the crystal field alone could not do. Thus in 
stead of having a single or a very narrowly split ground 
state the splitting could be large enough that at low 
temperatures some of the higher levels of the ground 
state would be empty. This was what we thought we 
needed for an optical maser. We really felt that if we 
were to get optical maser action we had to give ourselves 



every advantage and that is why we had not seriously 
considered the theoretical possibility that we could 
empty out the ground state by pumping. I presented this 
dark red ruby as a possible laser material, which would 
oscillate in the satellite line at 7009 or TO^lA or 
perhaps both, at the First International Quantum Elec 
tronics Conference in September of 1959- In emphasizing 
the advantages of the broad pumping bands in ruby and 
the four-level system made possible by the exchange 
coupling in dark ruby, I said briefly that the R lines 
were not suitable for laser action. Of course, it 
turned out later that both sets of lines can be made to 
lase . 

The proceedings of that conference, including my 
talk, were published very quickly and issued in February 
of I960, by the Columbia University Press. This is one 
of the very few occasions when I remember exactly when 
I wrote a paper. I had promised a manuscript by the 
time of the meeting, but as so often happens other 
things had prevented it. Therefore, I stayed at home 
for the first two days of the three-day meeting, wrote 
the paper and then came and delivered my talk on the 
third day. 

In that particular paper, I also described rather 
concretely the structure of an optical maser in the 
following words -- "The structure of a solid-state 
maser could be especially simple. In essence, it would 
be Just a rod with one end totally reflecting and the 
other end nearly so. The sides would be left clear to 
admit pumping radiation." 

Well, if we knew the material and the structure, 
why not do it? Now, when we know that construction of 
a laser can be so easy, it is hard to give a convincing 
answer to that question. But when we did not know how 
to assess the difficulties and since it had never been 
done, we believed that they might be formidable. For 
example, no solid, and especially not dark ruby, is free 
from variation of refractive index caused by strain. 
Thus if a plane wave started out at one mirror and was 
amplified as it passed down the rod, it would be dis 
torted beyond recognition before it could reach the 
other end and would not return nicely to the first 
mirror. Nevertheless, I did manage to find from Bill 
Mims, who was working on microwave masers, a rod of 
dark ruby. And as early as December 1958 I had the ends 
polished flat and parallel. I still have the order to 



have this done at Laboratory Optical Company. However, 
I did not acquire flashlamps and merely tried this half 
heartedly with a General Radio Strobotac which I had 
bought for measuring fluorescence lifetimes. This was 
not enough power and nothing happened. One other reason 
I did not push more agressively on it was that I was not 
sure Just how cold the crystal would have to be to empty 
the lower state of the optical transition. And besides, 
there were too. many interesting things to do in studying 
the spectrum. 

But others were active. At Bell Labs, Ali Javan 
had conceived the idea of a helium-neon maser making use 
of transfer of energy from metastable helium atoms 
produced in a gas discharge to particular excited levels 
of neon atoms. Actually, I had heard the idea of using 
a gas discharge even before we wrote our first paper. 
Willard S . Boyle at Bell Labs had mentioned this possi 
bility but he did not explore it seriously. He in fact 
described it in the context that processes in a semi 
conductor were similar to those in a gas discharge, and 
that it would be interesting to try and find a semi 
conductor analog of a gas discharge and that might pro 
duce population inversion which would permit optical 
maser action. Indeed Boyle has a patent on semicon 
ductor lasers. We did not mention this idea in our 
paper although both the gas discharge and semiconductor 
possibilities seemed real, because these were Boyle's 
ideas and not ours and it was up to him to publish them, 
but he did not do it. 

Ali Javan, however, did work out in some detail the 
properties of a particular system and he published a 
theoretical analysis in 1959- John Sanders from Oxford 
who visited Bell Labs in 1959 for eight months or so had 
another proposal using pure helium. People objected to 
Sanders' scheme in that the lower level would not have 
a short lifetime because of trapping of the radiation 
which was supposed to empty it, but there were objections 
in nearly everything anyone proposed and Sanders did 
spend some time trying it out. However, he had to re 
turn to England before any real conclusions were reached. 

Javan, whom I had known as a student with Charles 
Townes at Columbia and later as a postdoctoral worker, 
was and is an extremely ingenious and able scientist. 
His enthusiasm attracted others, most particularly 
Donald R. Herriott and he was able to arrange for the 
Laboratory to hire William R. Bennett, Jr. They made 


detailed studies of the processes in the gas discharges 
and Herriott developed optical components of great 
precision and quality for a helium-neon gas discharge 
optical maser. This all took considerable time, and in 
deed the research management at Bell Labs became con 
cerned whether this was all a waste of a rather con 
siderable amount of money or whether there was indeed 
some hope in it. I remember people went around and 
asked various opinions, but since these opinions were 
quite uniformly optimistic, the research was continued. 
But Javan and everyone else believed that the conditions 
for maser action in gases might have to be quite special 
as there are many processes tending to restore thermal 
equilibrium. I don't think anyone realized, as we now 
know to be true, that nearly any gas will lase if ex 
citation is violent enough. Indeed no one even con 
sidered looking at pulsed gas discharges until con 
siderably later. Perhaps that was because of the pre 
occupation with communications around Bell Labs, for 
which a continuous laser seemed the only really inter 
esting one. Indeed that was another obstacle which de 
tracted from my pursuing pulsed laser operation in ruby. 

Around the same time, C.G.B. Garrett and Wolfgang 
Kaiser, both of whom had worked previously on semi 
conductors, became interested in trying to develop a 
solid state optical maser. They were, very reasonably, 
attracted to the rare earth compounds and transparent 
crystals which, as we had noted in our paper, give strong, 
sharp fluorescent lines. With these materials, four 
level systems with any empty lower state would not be 
hard to find, but they do not have the broad pumping 
bands which make ruby so attractive. Any incoherent 
lamp used to pump them is likely to be largely wasted 
because only small portions of its output spectrum can 
be absorbed by the rare earth ions. 

At TRG , Inc. Gordon Gould and other associates in 
cluding Richard T. Daly had an Air Force contract to 
work on optical masers which was, at least in part, 
classified. They invited me to visit and give a talk 
in the spring of I960, and we exchanged ideas about work 
on spectroscopy of rare earth ions of the sort that 
might be useful for optical masers. However, everything 
we discussed presented formidable problems and an 
operating laser did not seem close. 

Sometime early in I960, we heard from one of Bell 
Labs management that Hughes Aircraft Research Laboratory 



in Malibu was also working on optical masers. This 
point did not register very sharply, because I did not 
know the people there at all well and did not believe 
that they had anyone with any optical experience. Nor 
did I know about the article which was published by 
Harold Lyons in the Hughes news magazine in which the 
use of a ruby as a three level maser material was pro 
posed. T.H. Maiman's name was familiar from work he 
had done on ruby microwave masers, including a paper at 
the Quantum Electronics Conference. 

I spent the spring semester of I960 at Columbia 
University as a visiting associate professor. I had 
been asked to do this because Townes was away at the 
Institute for Defense Analysis and it seemed good to 
have someone knowledgeable around in case his students 
had difficulties between his weekly visits, and also to 
teach courses. It was not possible for me to move to 
New York and so I commuted there daily, spending half a 
day or so at Bell Labs every week. This was an ex 
hausting ordeal and I ended up the semester quite ill 
with a succession of colds and an infection which took 
weeks to clear away. But during that spring, I received 
a paper from Physical Review Letters to referee. In it, 
T.H. Maiman described some experiments on excitation of 
ruby by a bright light or flash and made quantitative 
measurements on the fraction of atoms excited. Maiman's 
paper indicated that some percent of the atoms could be 
excited, although it was not possible to tell from the 
text whether he felt optimistic about being able to 
produce about ten times greater excitation needed to get 
more in the excited than in the ground state. I think 
I suspected that he was interested in optically pumped 
microwave masers. This manuscript was published in the 
May 15, I960 issue of Physical Review Letters. 

Late in June, there was a conference on Coherence 
in Optics at the University of Rochester and some of 
the Bell Labs people attended. They heard there, from 
Malcolm Stitch, that Maiman had succeeded in operating 
a ruby laser. This caused both excitement and puzzle 
ment. Then, in early July there was a press conference 
at which Hughes announced some information about Maiman's 
attainment of stimulated emission in ruby. Accompanying 
the press announcement was a photograph showing Maiman 
with a rod, very much as I had described, inside a flash- 
lamp. By that time, several people at Bell Labs were 
working with flashlamps, and as there were not many 
such lamps on the market, it was easily recognizable as 



a General Electric FT-52U . Preprints of Maiman's 
manuscript for publication were sent out to trad. 
magazine?, and we obtained a copy from a magazine writ 
er who came to Bell Labs to get our reactions and find 
out what Bell Labs was doing. There was some ^pticism, 
but it seemed quite convincing to me. So .many of he 
people vho were trying to produce various kinds of 
sta?e optical masers, began to -try to obtain laser ac- 
tion in ruby. 

Among them were Garrett and Kaiser, with some help 
from Walter Bond who was developing techniques r 
polishing and coating the crystals and also ^. Nelson 
.* P T Collins These were in different departments 

And so I went to ask Collins and Nelson about th. 
progress. They felt that they needed better .Liagno 
equipment than they had, in particular a better spectro- 
grapS to tell what was happening. I had acquired a goo 
spe?trograph for my research and so I Joined their effort 
and they moved their equipment down to my spec '"graph. 
Sithin a day or two they also had achieved laser action. 
I remember they were using a General Elect 'J "-52 U 
lamp which was rated at a maximum input of 
from a 1*00 microfared capacitor. At this rated output, 
the optical maser threshold was not achieved so they 
raised in input voltage to U200 volts, 200 volts above 
the manufacturer's rating, and their success was 
attained It does not pay to be gentle when you have a 
threshold effect! Lasers are nonequilibrium devices and 
you sometimes have to be fairly violent to get suffi 
ciently far away from equilibrium. 

We did not start out by seeing the beam, but by 
looking at an oscillograph showing the output of a 
photomultiplier which received the light <ed 
through the spectrograph. When laser action was achiev 
ed there was a brief burst of much more intense light 
than the fluorescence which was always emitted whenever 
you .Ited the ruby crystal at all. The experiment was 
of course quite improvised in many respects and the 
briKht light from the flashlamp lit up the whole room 
and made it very difficult to see what was going on 
other than what the instruments told us. In fact, w 
were not at all sure that the beam could be seen if 
there were a beam. The light from the ruby is at a 



wavelength so long that the eye is two hundred times 
less sensitive than in the green and the pulse lasts 
only about one two-thousandth of a second. 

But the first thing we could do was to find out 
whether the ruby optical maser had any of the pre 
dicted properties. One of these was that the light out 
put should be more monochromatic, that is, should be 
confined at a narrower band of wavelengths than that of 
spontaneous emission. It should be directional and it 
should be coherent, according to the theory of Townes 
and myself. We set out to try and check these points. 
The frequency spread could only be measured by flashing 
the laser repeatedly, photographing the output on an 
oscilloscope and changing the wavelength setting of the 
spectrometer between successive flashes. This was some 
thing of a problem, because the metal coatings on the 
ends of the ruby rod, which were usually gold, did not 
last long at the high intensities of the experiment. 

Directionality, which we now can see very easily 
by just looking at the beam, seemed hard to investigate 
because we did not know whether we could see the beam. 
The obvious way to do this was to put a camera focussed 
for infinity where it could receive the laser output and 
see whether the laser produced a small spot. A red 
filter would have to be placed over the camera to screen 
out the white light from the flashlamp. This was one 
of the things we were going to get around to but it 
finally began to be such an obsession with me that after 
one sleepless night I came in prepared to tell everyone 
that I was ready to fight to do this experiment next. 
At this point everyone agreed without a fight, and we 
found that the output was indeed focussed to a small 
spot indicating a beam divergence of about a hundredth 
of a radian, or a half a degree. 

Now Mairaan had indicated in his paper that he would 
not expect to get directionality because of reflection 
from the side surfaces of the crystal. So we deliberate 
ly left the sides of our crystal rough in order to mini 
mize reflection from the side walls. Thus I really did 
expect to get a beam and was gratified when it was ob 
tained. It was a bit crushing a few days later, how 
ever, when Garrett, Kaiser and Bond also observed a beam 
Just as good as ours while the sides of their crystal 
were polished. It was some months later before we 
realized that the pump light is actually focussed with 
in the crystal so that the degree of excitation is 



higher on the axis than it is near the walls. This 
means that while amplification is feeing obtained near 
the center of the crystal the outer parts are still 
absorbing and so reflections from the side walls are 
prevented . 

In our photographs, we noticed that the spot had a 
grainy substructure and so we found that the output 
came in filaments. This helped to explain why the beam 
was not even more perfectly directional than it was, as 
some diffraction spreading is inevitable from these 
small individual filaments. It also showed how laser 
action could occur in solid substances that were known 
to be highly imperfect. Indeed, study of the line- 
widths showed the ruby crystal, which we used for our 
earliest laser experiments, to be the most badly strainec 
one I have ever encountered. But somehow there happened 
to be some small paths over which light could find its 
way from one end mirror to the other and if the gain 
was high enough to overcome the diffraction losses in 
such a thin column, lasing could occur. 

Not very long afterward, Garrett and Kaiser took 
the trouble to box in the laser so that the stray light 
from the flashlamp could not reach the eye and light 
could only come out through a hole at the end of the 
ruby rod. They found, and everyone was excited to 
realize, that the beam indeed could be very easily seen 
as a bright red spot where it struck the wall. Maiman 
also apparently observed the directionality about the 
same time, for he submitted an abstract to the meeting 
of the Optical Society of America and his paper was 
presented at their meeting in October I960. 

One day, George Devlin asked "Is there any sign of 
hysteresis?" This would not be surprising because many 
oscillators do tend to show an overshoot when oscillatior 
starts or stops, and so we looked more carefully at the 
oscilloscope trace. Fortunately, we had acquired a 
Tektronics 555 dual beam oscilloscope in which one beam 
gives a magnified picture of a small portion of the 
trace displayed by the other beam. That is, we could 
delay the second beam sweep so that it covered an inter 
val of one hundred microseconds stretching between five 
hundred and six hundred microseconds after the initia 
tion of the flash. When we did, we could see that the 
output was indeed quite spiky and instead of being a 
burst of about five hundred microseconds it was in fact 
a series randomly spaced, very intense, one-microsecond 
pulses . 



To prove the coherence was somewhat more difficult 
experimentally. We knew that if the light coming out 
of the laser rod was spatially coherent, we could tell 
it by doing a Young's two-slit diffraction experiment 
with the two slits being right in the plane of the laser 
end mirror. Alternatively, we could have one wide single 
aperture and observe diffraction maxima and minima in 
the light coming out through this small opening. The 
troubles were purely the experimental ones of laying 
down the suitable patterns on the mirror and then having 
the mirrors hold together long enough to do the experi 
ment. We had not yet learned how to make dielectric 
mirrors suitable for ruby laser operations. The single 
aperture experiment was done first and the results 
showed definite coherence across the width of the slit 
which was about 50 micrometers by 150 micrometers. 

Between the two groups at Bell Telephone Labora 
tories we had amassed good experimental proof of the 
predicted properties of an optical maser. We therefore 
decided to submit a Letter for publication to Physical 
Review Letters and we set a cut-off date beyond which 
we would stop experimenting and finish the manuscript. 
The single slit diffraction pattern was obtained before 
the cut-off date but the double-slit was not until a day 
or two later. The double slit results were therefore 
submitted separately as a paper for oral presentation at 
a meeting of the American Physical Society. 

In writing this Letter we were concerned, of course, 
to present our findings clearly and concisely. However, 
we were afraid to use the title "optical maser," because 
we had heard some reports that Maiman's letter reporting 
his very important results had been rejected by Physical 
Review Letters and we thought that the reason might be 
because the editors of that distinguished Journal had 
previously expressed a disinterest in further papers on 
masers as being too concerned with devices for a Journal 
at the frontier of physics. We therefore called the 
paper "Coherence, Narrowing, Directionality, and Relax 
ation Oscillations in the Light Emission from Ruby," 
and it was coauthored by R.J. Collins, D.F. Nelson, 
W.L. Bond, C.B.G. Garrett , W. Kaiser and myself. I 
learned much later that the reason for rejection of 
Maiman's paper was quite different. The editor thought, 
mistakenly, that it was Just a small extension of the 
paper which he had published very recently, so that it 
violated their rule against serial publication. 


We also were concerned in that paper to be more 
specific than Maiman had teen in describing Just exact 
ly vhat we had used and had done. We therefore pointed 
out that our laser rods had been five millimeters in 
diameter and h . cm long even though this was about the 
dimensions of the one shown in the newspaper photograph 
of Maiman. We also specified that the lamp used was a 
General Electric FT-52U. It was a year later that I 
learned from Donald Buddenhagen that Maiman had in fact 
not used the FT-52U in his experiments. It had been 
shown in the press photograph because the lamps which 
he had actually used were all broken by that time. In 
a way that was fortunate, because the diameter of the 
FT-521* was larger than the lamp which Maiman used 
originally and had enough space in it to permit us to 
put in a small Dewar flask and do experiments at lower 
temperatures. We also learned much later that Maiman's 
original crystal had also not been as long and narrow 
as the one shown in the photograph, but that was not 
published until some time later. 

While this work was in the course of publication, 
the Laboratories felt it important to demonstrate that 
this work had something to do with communications which 
is the prime task of the Bell System. They therefore 
arranged to transmit pulses of laser light from the 
Holmdel Branch of Bell Telephone Laboratories to Murray 
Hill, an airline distance of about twenty-five miles. 
There was known to be a direct line of sight between the 
two laboratories, and there was a tower at Murray Hill 
designed for microwave propagation experiments to and 
from Holmdel. The experiment was carried out by Boyle, 
Collins and Nelson and they were quickly successful in 
not only seeing the beam by eye but photographing an 
oscilloscope trace recording in detail the individual 
pulsations or spikes which simulated a message that 
might later be encoded on a laser beam. All this was 
reported at a press conference soon after the publication 
of our Physical Review Letter and received widespread 
attention . 

Meanwhile, I had been continuing my studies of the 
dark ruby spectrum hoping to unravel the pair lines and 
find out which ones belonged to which kinds of pairs of 
chromium ions', nearest neighbors, second nearest and so 
on. While that had not gotten very far, I came to 
realize that the intensity of these pair lines was 
really strikingly high. This indicated to me that they 
were being pumped by the much more numerous isolated 



atoms. For example, if the concentration is a tenth of 
a percent, then only one in a thousand of the chromium 
ions will happen to have a neighbor at the adjacent 
particular crystal lattice site. Yet, even though the 
pairs could not be as numerous, the lines could be as 
strong or even stronger than the lines of the isolated 
ions. Indeed the absorption was relatively weak, as it 
should be since paired ions are few, but the emission 
was strong. This indicated that there was an even more 
efficient method of exciting the pair lines than I ex 
pected and, while I did not want to get into competition 
with all those who were doing laser work, I finally 
decided to try out the pair-line ruby laser. By that 
time, in the fall of I960, I had acquired a power supply 
and large flashlamps. The experiments were successful 
and George Devlin and I found that laser action could 
be obtained on either of the strongest pair lines 
separately or simultaneously, with or without laser 
emission at the R-line. This gave an interesting proof 
that the 7009A 5 line and the TO^lS line came from distinct, 
separate systems and that they are both separate from 
the R-lines . 

We had avoided the word maser in the paper which 
Bell Laboratory people had sent to Physical Review 
Letters. But it was apparent by that time, that not 
everyone had understood that what we were talking about 
was really coherent stimulated emission from atoms in a 
resonator. I therefore decided that I would use the 
term optical maser in this paper, even if that did mean 
automatic disqualification from Physical Review Letters, 
and sent it instead to the slightly slower but equally 
reputable Physical Review. Physical Review Letters, 
which provides quick publication of important new re 
sults, has to be somewhat selective and must reject a 
substantial fraction of the papers submitted if it is to 
maintain a rapid publication schedule. Thus they can 
sometimes apply somewhat arbitrary criteria like the 
ban on masers which I supposed to be in effect. In 
deed they must do so, because the initial discovery in 
any field is often followed by a growing flood of 
follow-up papers of gradually diminishing urgency. 

However, somewhat to my surprise the paper ended 
up being published in Physical Review Letters. It 
happened because on the very same day that the paper by 
myself and Devlin arrived at the editorial office of the 
two Journals, they also received a paper by I. Wieder 
and L.R. Sarles reporting stimulated emission from the 



pair lines in ruby . The first I knev of it was when the 
Wieder-Sarles paper was sent to me to referee. I of 
course said that it looked like good work to me. Then 
the editors were faced with a necessity of treating both 
comparable papers on a similar basis, either both in 
Physical Review or both in Physical Review Letters and 
they chose the latter. Thus both papers describing laser 
action in dark ruby appeared in the February 1, 196l 
issue of Physical Review Letters. Though the dark line 
ruby laser has been confirmed, it has not been very much 
explored because it has so far been operated at temper 
atures considerably below room temperature. 

Around the end of November, I960 I received a 
telephone call from Mirek Stevenson, who had been a 
graduate student with Townes at Columbia but was by that 
time at the IBM-Watson Research Laboratory. He told me 
that he and Peter Sorokin had obtained laser action in 
two more substances, calcium fluoride containing di 
valent samarium ions and calcium fluoride containing 
trivalent uranium ions. Both of these materials opera 
ted at cryogenic temperatures. Sorokir. and Stevenson's 
results were already in course of publication in the 
IBM Journal and appeared a day or so later. I remember 
this event not only because it was one of the earliest 
laser materials, probably the second and third laser 
materials to operate, but also because a day or so 
later when the IBM group announced their results I had 
a telephone call from a reporter on the New York Times 
asking for comments on it. Fortunately, by that time I 
did know about it and I was able to help him get his 
story straight. For instance, I suggested that it was 
important for him to mention that the samarium and the 
uranium ions were respectively divalent and trivalent, 
and so it appeared in the New York Times story. At that 
time, there were not as many good science writers as 
there are now, and I have often been impressed by the 
care in which the New York Times took to verify their 
stories . 

The other memorable aspect was that Stevenson told 
me sometime later that he had accepted the challenge of 
finding an optical maser material as a management prob 
lem. Even as a graduate student he had been very inter 
ested in investing and had been extremely successful in 
the stock market. Subsequently he founded several com 
panies, mostly in the field of investment and investment 
research. But when presented with the problem of quick 
ly constructing an optical maser he went at it by seeking 



out the sources of supply for each of the components, 
that is the crystals, the flashlamp and the power supp 
ly and assembling them from these sources so that the 
experiment could be done in a hurry. This contrasted 
somevhat with a do-it-yourself approach which most of 
the others in the field followed. In this case it cer 
tainly did pay off, because Garrett and Kaiser at Bell 
Labs had been working on similar substances, but had not 
been able to reach the point of getting suitable samples 
installed in suitable equipment for tests. Undoubtedly, 
Sorokin also played an important part in this work for 
he has remained active and has indeed produced several 
of the most important advances in laser physics since 
that t ime . 

The first public demonstration of an operating 
laser was given at the Nerem Electronics Meeting in 
Boston on November IT, I960, accompanying my talk. 
Lewis Winner, who organized the Nerem Meeting had in 
vited me early in the summer, before our experiments on 
lasers had advanced very far. Fortunately, by the time 
of the talk our results on the properties of ruby lasers 
had been published and my colleagues agreed that I could 
talk on them as well as about my own theoretical work. 
A large ruby laser power supply was transported to the 
hall and set up and we demonstrated that a bright red 
flash could be produced and shown as a momentary bright 
spot on the screen. We knew of nothing more spectacular 
to do with it at that time. 

A few months later, in January of 196l, George 
Devlin and I were able to load an optical maser into the 
back of a station wagon and drive it to Toronto for a 
similar demonstration at a meeting of the Royal Canadian 
Institute. But by June of 196l, Bob Ammons had built a 
really portable ruby laser for Robert J. Collins to take 
and display at the International Commission for Optics 
Meeting in London. It used a commercial 200 watt-second 
photoflash power supply and a small ruby rod with a 
flashlamp and a little elliptical cylinder reflector. 

During the same period, we were finding out some 
things that these early lasers could do. Willard Boyle 
showed that if the beam from a ruby laser was focused to 
a small spot on the surface of an absorber, it would 
vaporize a bit of that material, producing a white-hot 
Jet. The temperature was so high that even the most 
refractory materials, such as carbon, could be instant 
ly vaporized. Boyle realized that lasers could then be 



used for drilling holes and all sorts of materials proc 
essing. Indeed within the next few years the Bell Sys 
tem, in their Western Electric manufacturing division, 
put lasers to use drilling holes in diamonds which were 
to be used for wire-drawing dies. Again, Boyle did not 
publish his results but I was able to use photographs of 
one of these laser produced Jets to illustrate in artic 
les which I wrote for Scientific American and the Solid 
State Journal. Very soon people began to drill holes 
in razor blades by focusing ruby lasers onto them. As 
lasers were made larger, it became possible to drill 
holes simultaneously through several razor blades 
stacked one behind the other. Soon, someone suggested 
that laser output power should be measured in Gillettes.' 

From the beginning, writers of popular accounts in 
the newspapers and some people in the military expected, 
or at least hoped, that lasers would fulfill the old 
dream of a death-ray. We had a good bit of fun with 
this notion, which was so very far beyond the capabili 
ties of even the largest lasers. I have often shown a 
slide of our "death-ray countermeasur es , " which I made 
at that time. It shows some suits of shining armor, of 
the kind that knights used to wear. It was easy to cal 
culate that an unprotected two hundred pound man could 
be completely evaporated by about two hundred million 
one-Joule shots from a typical ruby laser. If we could 
deliver them at the rate of one per second, which was 
rather better than we could do, he would only have to 
stand there for six years. Still, it was obvious even 
then that, once the principle was established, you could 
expect ultimately to have very large sustained as well 
as pulsed powers even though we did not yet know how to 
achieve them. 

But the problem remained of what one could do with 
the small, expensive, heavy pulsed lasers then existing. 
I moved to Stanford University in September 196l and a 
few months later, in January of 1962 appeared on a local 
television program called "Science in Action." I wanted 
to illustrate my remarks with experiments but had only 
one very small ruby laser not even big enough to drill 
a hole in a razor blade. G. Frank Imbusch, who was then 
one of my graduate students, suggested that we could 
break a balloon with it and this was tested and found to 
be possible. So Imbusch, Linn Mollenauer another student, 
and I went to the studio. While I was rehearsing, the 
students fixed the balloon with a cardboard base and 
fins to look like a rocket ship, and positioned it in 



front of the laser. I can assure you that I was much 
concerned as to whether the thing would actually work or 
not as the program was being broadcast live. Fortunate 
ly, it did work and I began showing balloon-breaking 
demonstrations. A year or so later, when I was in 
Washington I spoke at a meeting of a group of the Inter 
national Scientific Radio Union (U. R.S.I.) which happened 
to meet at the same time as the Optical Society. We 
were therefore able to make a demonstration with a large 
ruby laser kindly provided by Trion Instruments (later 
Laser Systems, Inc.). With this laser we could not on 
ly break a blue balloon but we could let the light pass 
first through a red balloon which did not absorb the red 
light and was unaffected. This made it a more spectac 
ular demonstration and showed that the color of the 
light had something to do with it. 

Still, the mind works slowly and it was not until 
near the end of 19^3 when it occurred to me that the 
balloon breaking experiment could be done with a dark 
blue balloon inside a clear outer balloon. I realized 
this as I was sitting with my son at the San Francisco 
Zoo and watching other children carrying such balloons. 
Of course such a demonstration is a very good illu 
stration of something that could be done with a laser 
and not easily in any other way, for the outer balloon 
remained unharmed as it did not absorb the light. This 
is also a good illustration of the use of lasers to 
accomplish things that are at otherwise inaccessible 
places, for example as. they are used for surgery on the 
retina of the eye. To make the stunt more effective Ken 
Sherwin, the technician with our research group, built a 
small, portable ruby laser into the housing from a toy 
ray-gun replacing the flashlight with which the toy had 
been sold. I showed this first at the meeting of the 
American Association for the Advancement of Science at 
Cleveland in December, 1963. It was at that time, while 
getting ready for the A.A.A.S. Meeting, that I realized 
that laser erasing was possible although my little ray- 
gun did not have enough power to erase more than a small 
portion of a typewritten character. 

The idea of a laser eraser appealed to me, not only 
because it was elegant and useful, but also because it 
pointed in quite the opposite direction to the thinking 
of most of the efforts seeking laser applications. Here 
was something that certainly could be done, and for 
which there was a very large potential market. The only 
problems were engineering and economic. In this it 



contrasted sharply with attempts to make laser weapons 
for which there were very large amounts of money, but 
which no one knew how to do. Naively, I thought that I 
could Just announce the idea of a laser eraser and 
people would start to make them. When this failed, I 
was urged to apply for a patent and did. It was appar 
ent that nobody would make the substantial investment 
to produce laser erasers without at least the protection 
of a patent. The patent was finally granted in 1970, 
but it may be that even that will not be sufficient to 
overcome the economic obstacles to laser eraser use un 
til suitable lasers are put into quantity production 
for some other purpose. 

Perhaps a little should be said about the atmos 
phere surrounding the laser research and the way in 
formation was communicated. The initial paper by 
Townes and myself setting forth the requirements for an 
optical maser and indicating the properties needed for 
suitable materials did inspire both considerable inter 
est and considerable skepticism. A number of very good 
reasons were advanced why lasers might not ever work, 
but some people did take the possibilities seriously 
enough to work on them. When lasers were actually 
demonstrated in I960, they did cause considerable ex 
citement both in the popular press and in the scientific 
and engineering community. Peter Franken had described 
later, at a Symposium of the Optical Society of America 
in 1971, the atmosphere at the Optical Society sessions 

on lasers in the spring of 196l. " I recall now, 

Just ten years ago on the nose, the first meeting of 
any professional society on the laser. That was in the 
spring meeting of 19&1 in Pittsburgh of this Society and 
many of you may not have had the opportunity to be there. 
Let me spend a minute and tell you what it was like: 
sheer panic. At most meetings, Just to give you one 
parameter, at most meetings people carry some cameras 
and a man will show a slide, that is have a slide shown 
at his request and you'll hear a few clicks. At that 
meeting every time a slide was projected it was like the 
sullen rumble of semi-quieted, semi-automatic fire. In 
fact the high point in that meeting occurred during my 
good friend Arthur Schawlow's lecture, which was a chalk 
talk and he was talking about some of the puzzles and 
mechanisms of the ruby laser. I recall a real key point, 
I forget the rest of your talk, but the one point I 
remember was your saying "We think that there are two 
mechanisms operative in the spiking of the ruby laser," 
which was a big puzzle then. He went to the blackboard, 



picked up a piece of chalk and wrote down the number 1, 
turned away from the blackboard and a dozen cameras 
went off. This is the kind of panic that was going on 

" I think Franken must have picked up a bit of 

the excitement himself, for he soon borrowed a laser 
and then with his associates Hill, Peters and Weinrich 
achieved for the first time optical harmonic generation, 
thereby ushering in the new and ever growing field of 
nonlinear optics. 

Not only were there scientists, but the early 
laser meeting attracted a very large number of out 
siders such as engineers in aerospace companies, who 
were eager to garner any scrap of knowledge about these 
new devices which they might incorporate in systems and 
sell to the government. To me, the high point of this 
general excitement over the prospects of lasers came at 
the meetings sponsored at the Meeting of the Polytechnic 
Institute of Brooklyn in New York in March of 1963 
where it seemed that every few feet along the corridor 
there was someone else asking me some question or other. 
But then the excitement subsided as we expected and 
people got down to the serious business of learning more 
about the operation of lasers, finding new ones and 
finding out what they could do. Moreover, the Tower of 
Babel effect become more noticeable as individual 
specialties within the laser field grew large enough so 
that specialists from areas could hardly communicate 
with others and indeed did not feel that it was neces 
sary to do so very often. 

What did I learn from all this? Many things, al 
though no golden rule on how to do good research. To 
every suggested maxim for guiding research, it is easy 
to find a counter example. I have made many mistakes 
and have seen my colleagues make mistakes either over 
looking something which later seemed obvious or even 
denying it. Yet a good forthright error is often a 
stimulating thing as it challenges others to prove you 
wrong. Many times new workers in the field seemed 
quite foolish and they foundered initially but then 
suddenly they were productive and producing their own 
original contributions. 

It also appears that there are times when one 
should attack a problem head-on, seriously analyzing 
the steps needed to attain a desired goal. This was 
what Townes and I did in our analysis of the conditions 
for an optical maser. At other times it is better to 



admit that ve do not know enough and Just sit back and 
add fundamental knowledge, depending on both instinct 
and logic to pick out potentially fruitful areas. 

I also believe it is a good thing for some of us 
should mix pure and applied research committing our 
selves fully to neither. Thus Townes could, as he did 
in the late l*0's, study deeply the processes in the 
ammonia molecules as an example of the interaction be 
tween molecules and electromagnetic fields. From this 
study, he was able to obtain enough knowledge to invent 
the maser. But if he had not had the practical inter 
ests in finding out about applications, then that 
particular piece of knowledge might not have ever found 
its way to the mind of a person interested in generating 
electromagnetic waves. 

As one looks at the parallel histories of other 
new fields of technology such as electronics or avia 
tion, one cannot help realizing that lasers are still 
in a very early stage of their development and that 
many of the most exciting experiences of discovery are 
st ill to come . 





Masers and Lasers 


CHARLES H. Townes likes to tell the story of how he 
invented the maser. In the spring of 1951, while he 
was a Professor of physics at Columbia University and I 
was a postdoctoral research associate in his laboratory, we 
both attended the meeting of the American Physical So 
ciety in Washington. As Townes remembers it, we shared 
a room at the Franklin Park Hotel. He had several small 
children and so was used to waking up early, while I, being 
then a bachelor, was used to sleeping later in the morning. 
When this happened one day, he dressed quietly in order 
not to disturb me and went outside to enjoy the pleasant 
spring morning in Franklin Park. There he thought about 
the Office of Naval Research's Millimeter Wave Com 
mittee which was to meet later that day. Two years of 
meetings had so far failed to produce any major break 
through in ways of generating radio waves shorter than the 
centimeter lengths of the microwave region. At that point 
he realized how to use molecules rather than free electrons 
to generate these waves. 

Townes had for several years realized that the sharp 
resonances in atoms or molecules could act as radio circuit 
elements. He had even obtained a patent on some of these 
uses while at Bell Telephone Laboratories. He was also 
aware that whereas ordinary molecules absorb waves, ex 
cited molecules could amplify by the process of stimulated 
emission. Lamb and Retherford [l] had remarked on that 
possibility. But there seemed to be nearly insuperable 
problems. Stimulated emission is the true negative of ab 
sorption, and the same atoms or molecules can do either. 
An atom in a lower energy state absorbs radiation, thereby 
being excited to a higher state with more stored energy. 
Amplification, on the other hand, occurs when an elec 
tromagnetic wave interacts with atoms already excited to 
upper energy levels and stimulates them to emit, thereby 
enhancing the wave at the expense of the atom's stored 
energy. Thus if there are more atoms in the higher energy 
state, amplification will occur. But far more commonly, 
atoms in the lower state are more numerous and so ab 
sorption predominates. Indeed, in thermal equilibrium at 
any temperature, there are always more atoms in lower 
energy states than in upper ones, so that absorption is 
commonplace and amplification by stimulated emission 
is never observed. Thus even though the concept of stim 
ulated emission had been introduced by Einstein more 
than thirty years earlier [2], and its existence had been 
confirmed experimentally by Ladenburg [3], the possibility 
that it could be dominant seemed, to most scientists, so 
remote as to be not worth considering. 

Manuscript received March 5, 1976. 

The author a with the Department of Physics, Stanford University, 
Stanford, CA 94305. 

Yet, radiofrequency and microwave spectroscopy had 
blossomed in the 1940's for studying atoms, molecules, and 
nuclei. With even a modest amount of radio power it was 
easy to saturate an absorption and drastically alter the 
numbers of atoms in the various quantum states. Indeed 
one had to be careful to avoid distorting the spectra by 
saturation. In the limit of high radio wave intensity, the 
populations of the upper and lower states were equalized. 
This process would not invert the population distribution 
and produce the excess of upper state atoms needed for 
amplification. Nevertheless radiofrequency resonance 
studies showed that it was really possible to get far away 
from equilibrium and to drastically alter the absorption. 

There was one other clue. Purcell and Pound at Harvard 
University [4], when studying nuclear magnetic resonance 
found that the relaxation time of lithium nuclei in lithium 
fluoride is extraordinarily long, fifteen seconds at room 
temperature. When a magnetic field is applied to the 
crystal, the nuclei of the lithium atoms, acting as the tiny 
magnets that they are, precess around the magnetic field. 
After a time, they exchange energy with the crystal's 
thermal vibrations, and at very low temperature would all 
settle down with their magnetic moments pointing in the 
direction of the magnetic field. But at room temperature 
a smaller fraction of the spins are thermally excited to the 
higher energy state where they are opposite to the field 
direction. Transitions between the two states can be in 
duced by the absorption or emission of radio waves, and 
ordinarily absorption predominates. Purcell and Pound 
discovered an ingenious method for rapidly reversing the 
spin direction, and this resulted in a momentary change 
of the nuclear resonance signal from absorption to stimu 
lated emission. They did not discuss the possibility of 
amplification, and their effect was probably just a small 
reduction in the losses of the circuit coupled to the crystal. 
Indeed when Joseph Weber three years later in 1953 con 
sidered seriously whether useful amplification by stimu 
lated emission could be obtained, he discussed the mo 
mentary gain from inverted spin systems and found it to 
be very small. 

But when Townes, on that spring morning in 1951, 
thought about how to make an oscillator or amplifier using 
stimulated emission, he thought about gaseous molecules 
and, in particular, ammonia. He and his students had in 
vestigated many aspects of this molecule which so strongly 
absorbs microwaves. Then he realized that there was a way 
to separate excited molecules which could emit microwaves 
from unexcited absorbing molecules. If a beam of ammonia 
molecules passed through a suitable electric field gradient, 
the molecules would be deflected. Most important, mole 
cules in these two lowest states would deflect in opposite 
directions, and so they would be spatially separated. An 

Copyright 1976 by The Institute of Electrical and Electronics Engineers, Inc. 



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Fig. 1. Page from C. H. Townes' notebook recording the idea of the 
original maser, 1951. 

aperture at the end of the beam could then be positioned 
to accept only molecules in the excited state, and to permit 
them to pass into a cavity resonator. 

The resonator would be tuned to the microwave fre 
quency that the excited ammonia molecules could amplify, 
and would greatly increase the coupling between the 
molecules and an electromagnetic wave. Thus even a 
moderate, attainable number of excited ammonia mole 
cules could eive observable amplification. Moreover, if 

excited molecules could be supplied fast enough, the rate 
of stimulated emission would exceed the resonator losses. 
Then a sustained time-coherent oscillator would be pro 
duced from the stored energy of incoherently excited 
molecules. Fig. 1 shows Townes' notebook entry recording 
the invention. 

Townes was optimistic that such a molecular oscilla 
tor-amplifier would work and so he began to build one with 
James Gordon, a graduate student, and Herbert Zeieer, a 




Ffc 2. C. H. Townes and T. C. Gordon with the second ammonia maser. 
T. C. Wang on the right iUnd by the fint maer, 1954. 

research associate. He did not feel it appropriate to publish 
the ideas until they had experimental confirmation. 
However, he talked about it quite widely and described it 
in the Columbia Radiation Laboratory's Progress Report 
The project was difficult and complex, but oscillations 
were obtained from an ammonia beam device early in 1954 
[6]. It was dubbed a "MASER" an acronym for Microwave 
Amplification by Stimulated Emission of Radiation. This 
first molecular oscillator produced a pure frequency mi 
crowave output of about 10-" W at 23.87 GHz. The output 
frequency was primarily determined by the molecular 
resonance, so that its oscillation frequency could be used 
as a frequency standard or atomic clock. As an amplifier, 
it gave excellent low-noise performance but the narrowness 
of the spectral lines, which made them so suitable for a 
wavelength standard, implied a very narrow bandwidth 
and little tunability. Fig. 2 shows Townes with students 
J. P. Gordon and T. C. Wang with the first ammonia-beam 

In the three years between Townes' conception of the 
maser and publication of the first results, others had been 
seeking the way to a molecular amplifier. In 1953, J. Weber 
discussed the possibility of obtaining traveling wave am 
plification and mentioned the possibility of vising nuclear 
or electron spins [5]. However, he did not propose a par 
ticular workable material or the use of a resonator. N. G. 
Basov and A. M. Prokhorov early in 1954 proposed a 
method of selecting out excited molecules in a molecular 
bam, quit* similar to Townes' [7]. Later Basov and Pro 
khorov suggested another possible method of obtaining 
ctive molecules for a maser oscillator [8]. They pointed 
out that if th atomic or molecular system had three or 
more energy levels, a high-frequency electromagnetic field 
could excite enough atoms for amplification. The high- 
frequency field would be tuned to excite atoms from the 
lowest to the highest of the three quantum states. If strong 
enough, it would equalize the number of atoms in these two 
itates and there would then be no more absorption but also 
no amplification at that frequency. However, there could 
be amplification at the frequency corresponding to a 

transition between the upper and intermediate levels or 
to that between the intermediate and lower levels. In these 
three-level schemes, the output frequency would be lower 
than that of the pumping field. Thus the three-level maser 
did not offer a way to produce a shorter wavelength shorter 
than that of the driving oscillator. Basov and Prokhorov 
did not discuss a specific molecular or atomic system, and 
the importance of this idea was not widely appreciated at 
the time. Indeed, Townes had also recognized that masers 
could be pumped by radio waves or even by light and re 
corded that in his notebook in 1954, but had not bothered 
to publish because it was not yet specific. Attention then 
turned to electron spins in paramagnetic solids, which gave 
strong microwave resonances which could be tuned by a 
wide range by an applied magnetic field. Combrisson, 
Honig, and Townes [9] were able to produce momentary 
microwave amplification effects from donor atoms in sil 
icon after suddenly inverting their electron spins by the 
method of adiabatic fast passage. In the following year N. 
Bloembergen [10], not knowing of Basov and Prokhorov's 
1955 paper, independently discovered the three-level 
pumping method and made a detailed proposal for 
three-level, solid-state masers using nickel-zinc fluosilicate 
and gadolinium-lanthanum ethyl sulfate. A few months 
later, H. E. D. Scovil, G. Feher, and H. Seidel [11] obtained 
continuous-wave maser amplification in gadolinium- 
lanthanum ethyl sulfate with relaxation rates altered by 
the addition of 0.2 percent cerium ions. 

During the next several years, work on solid-state 
three-level masers grew rapidly, and they were quickly 
applied as sensitive low-noise preamplifiers for microwave 
astronomy, satellite communications, and radar. New 
materials were found, such as potassium cobaltr-chromium 
cyanide by A. L. McWhorter and James W. Meyer [12], 
and ruby by G. Makhov, C. Kikuchi, J. Lambe, and R. W. 
Terhune. Both Bloembergen's and Townes' groups built 
masers, the former using the potassium cobalt-chromium 
cyanide and the latter using ruby. Consequently, when 
Townes and Bloembergen shared the Liebmann Award of 
the Institute of Electrical and Electronic Engineers in 
1959, Townes had the ruby from his radioastronomy maser 
made into a pin and presented it to his wife. On the way 
home from the awards ceremony, Mrs. Bloembergen asked 
her husband why he didn't do something like that from his 
maser. All Bloembergen could do was reply "But my maser 
was made of cyanide, dear!" 

The rapid growth of maser research for low-noise am 
plifiers and wavelength standards is strikingly shown by 
the large number of papers, and especially the many lab 
oratories represented, at the first Quantum Electronics 
Conference in September of 1959. But already there was 
competition from parametric amplifier*. Indeed one very 
able scientist at Bell Telephone Laboratories decided that 
masers had no future in communications, and so he 
changed to working on parametric amplifiers. 

While Townes and his itudenU had invented the acro 
nym "MASER" from Microwave Amplification by Stim 
ulated Emission of Radiation, very soon there was talk of 
imilar acronyms for other, as yet unknown, devices. These 




included RASER (Radio Frequency), IRASER (Infra 
Red), LASER (light), UVASER (Ultraviolet), XRASER 
(X Rays) and GRASER (Gamma Rays). Of all these, the 
term LASER has subsequently become an accepted, 
commonly used term. 


When Townes first thought about the ammonia mo 
lecular-beam oscillator in 1951, he had hoped that it could 
be made to work on a rotational transition and generate 
a wavelength in the half-millimeter region. But it had 
turned out to be more convenient to work in the centimeter 
region, where techniques were well known. So the problem 
of using atomic systems to generate coherent radiation of 
wavelengths shorter than the visible region remained un 
solved when Townes and I turned our attention to it in 

Although I had been a research associate at Columbia 
University with Townes and had been excited by the maser 
concept when I heard it in 1951, 1 did not work on it. By 
then I had accepted a position in the physics research 
group at Bell Telephone Laboratories. There I was hired 
to work on superconductivity, and so that was what I did. 
On weekends I worked with Townes on a book, Microwave 
Spectroscopy, which was published in 1955. But by 1957, 
I felt that the time was right to take a serious look into the 
possibilities of extending the maser principle to shorter 
wavelengths. I wanted to identify the difficulties and see 
if solutions could be found for them. To start, I had only 
some vague notions about using ions in crystals, which do 
sometimes have fairly sharp resonances in the far-infrared 
region. As Townes was then consulting with Bell Tele 
phone Laboratories, 1 mentioned this to him. He also had 
begun to think about the problem, and so we decided to 
work on it together. 

By that time (around October 1957), Townes felt that 
it would be better to jump over the difficult far-infrared 
region and try to build a maser in the near-infrared or even 
visible, where so much more was known. Moreover, he had 
some ideas about one particular possible system using 
thallium atoms. He had made some notes and arranged to 
send me a copy. 

We both realized that incoherent light from a lamp could 
be used to pump three-level or four-level optical masers, 
analogous to these already in use at microwaves, if the 
pumping light is bright enough. The fact that the pumping 
light would be incoherent would not matter, any more than 
the independent arrival times of the molecules of the am 
monia beam to its resonator. In either case, the output 
wave's coherence would be determined by the wave stored 
in the resonator. The excited atoms would be stimulated 
to emit radiation in phase with the stored wave. 

The first problem was to see how much exciting light 
would be needed and see if that would be obtainable from 
any conceivable lamps. To begin with, it seemed best to 
study atoms, and preferably fairly simple atoms such as 
the alkali metals. The spectra of these atoms were already 
quite well measured and understood, so that we could look 
up the energy levels in the monumental Atomic Energy 

Levels [14], a National Bureau of Standards Publication 
edited by Charlotte Moore-Sitterly. Information on the 
relative and absolute strengths of the various spectral lines 
was much scarcer, but there was some help from the tab 
ulation of L. Biermann in the Landolt-Bdrnstein Tables 
[15]. Moreover, in the book Resonance Radiation and 
Excited Atoms [16], by A. C. G. Mitchell and M. W. Zem- 
ansky, there was a wealth of stimulating information about 
the absorption and emission of light from alkali atoms. 
Finally bright alkali-metal lamps could be made, and were 
already commercially available, which emitted just those 
wavelengths heeded to excite other alkali atoms. 

Townes had the maser equation, which would permit us 
to calculate how many excited atoms would be needed for 
optical maser oscillation. This equation expressed the re 
quirement that there must be enough excited atoms to 
ensure that stimulated emission will supply energy to the 
optical electromagnetic field faster than the field will lose 
energy at the resonator walls. If the atom's oscillator 
strength (a measure of the effective number of electrons 
in a classical oscillator that would absorb or radiate as well 
as the atoms at the particular wavelength) is large, a small 
optical field will stimulate strong emission and only a few 
excited atoms will be needed. If the oscillator strength is 
small, as it is for "forbidden" transitions, correspondingly 
more excited atoms will be needed for maser oscillation. 
For a microwave gas maser, similar statements could be 
made, except that the custom is to talk in terms of the 
transition dipole moment rather than oscillator strength. 

However, there is one important difference between the 
optical and microwave cases. In the optical region, an ex 
cited atom rapidly loses its stored energy by spontaneous 
emission. Like stimulated emission, the rate of spontane 
ous emission is also proportional to the oscillator strength. 
Thus when the oscillator strength is high the excited atoms 
decay quickly and must be replaced quickly. As a result, 
the rate at which excited atoms must be supplied is inde 
pendent of the oscillator strength. A forbidden spectral line 
could be as usable for an optical maser as an allowed line 

Our study of the maser equation revealed another in 
teresting fact. A light wave in the resonator would lose 
energy only at the walls, and would gain it by stimulating 
emission as it passed from one wall to another. Thus it 
would be helpful to make the device fairly large, very much 
larger than one optical wavelength. Then the stimulated 
emission could take place over a relatively long path be 
tween wall reflections. The greater this distance, the less 
the required density of excited atoms would be. Thus we 
could reduce the power density requirement for the 
pumping radiation by making the device larger. 

With these considerations in mind, we made an estimate 
of the pumping power requirements for an optical maser 
using potassium vapor. The excitation would be supplied 
at a wavelength of 404.7 nm and the output would be in the 
infrared at either 3.14 or 2.71 tan. Assuming, for the cal 
culation, convenient-appearing dimensions of 10-cm 
length and 1 -cm crosssection, we estimated that a pumping 
power of 1.2 mW would be needed. This seemed quite at 
tainable, particularly since measurements by our colleague 



Robert J. Collins (now at the University of Minnesota) 
showed that outputs of up to 0.6 mW at the required 
wavelength could be obtained from a single commercial 
lamp. Brighter and bigger lamps could very probably be 
made, and the dimensions of the structure could be 
changed if needed. 

Throughout these discussions, we had always thought 
of a resonator which, unlike that of a microwave maser, 
would be very large compared with a wavelength of the 
radiation. This seemed to be rather obviously necessary, 
for optical wavelengths are of the order of 1/20 000 cm. 
Even if a tiny single-wavelength resonator could be fab 
ricated, it would be too small to hold enough amplifying 
atoms to overcome its losses. On the other hand, a large 
resonator would not provide mode selection in the way that 
a microwave maser's cavity does. A resonator of centimeter 
dimensions would be capable of sustaining very many 
different modes of oscillation, even within the small 
bandwidth that the excited atoms could amplify. Martin 
Peter, another Bell Laboratories colleague who is now at 
the University of Geneva, particularly urged us to worry 
about the problem of mode selection. He feared that the 
output of an optical maser, even if it did oscillate, would 
be a jumble of rapidly fluctuating modes of oscillation, 
difficult to distinguish from spontaneous .radiation. 
Townes felt rather that the problem might not be crucial, 
since some perhaps moderate number of modes would have 
lower losses than the others and would be most likely to 
attain oscillation. While the oscillations in the favored 
modes would fluctuate, they might well be quite distinc 
tive. In all, he felt that lack of a better method should not 
prevent going ahead with work on systems in which modes 
were not well controlled. 

At this point, I recalled that the resonant modes of a 
large box can be thought of as waves traveling in various 
directions between the walls of the box. Their wavelengths 
would be restricted by the fairly narrow bandwidth of the 
amplifying spectral lines. If we could restrict their direc 
tions, we would drastically reduce the number of available 
modes of oscillation. I thought of such things as having one 
or more walls made up of diffraction gratings. Then I re 
alized that the problem did have a simple solution. We 
could remove almost all of the walls of the box, and leave 
only two small mirror-like sections facing each other at the 
ends of a long pencil-like column of amplifying material. 
As long as the end surfaces were much larger than a 
wavelength they would act as good mirrors and reflect 
waves straight back and forth between them. A wave 
traveling in a direction inclined at even a small angle to the 
axis would miss the end mirror and be lost. When I told 
Townes about this idea, he pointed out that the directional 
selection would be even better than I thought, because the 
amplification would permit a wave in the selected direction 
to make many passes back and forth along the axis. An 
off-axis wave might make one or two traversals but would 
then be lost. Even though a detailed theory of the laser 
resonator came considerably later, [17], [18] it seemed clear 
that it would indeed select modes and produce a narrow 
beam. These detailed calculations confirmed our conclu- 


sion that the optical maser modes would be very nearly 
plane waves. 

Thus we knew we had a suitable structure and several 
likely materials, and were convinced that an optical maser 
could be made. Still, it had never been done and there 
might be unforeseen problems. So we decided to publish 
our analysis, and it appeared in the December 15, 1958 
issue of Physical Review [19]. Townes then started a 
graduate student, Herman Cummins on a project to try 
and build an optical maser using potassium vapor. He was 
later joined by another student, Isaac Abella, and by Dr. 
Oliver S. Heavens, an English scientist who was already 
well known for his work on optical properties and uses of 
thin films. Considerable progress was made, but eventually 
the successes of other researchers led the Columbia Uni 
versity group to abandon work on potassium for easier 

Our paper on optical masers attracted considerable in 
terest. Some people had serious doubts that it would even 
be possible to build an optical maser, and some very 
plausible arguments were advanced to prove that it would 
not work. But a number of others seriously sought suitable 
materials and ways to activate them. At Bell Telephone 
Laboratories, W. S. Boyle mentioned the possibility of 
using a gas discharge, but did not explore it seriously. He 
was interested in semiconductors and carried his analysis 
far enough to get a patent on a laser using recombination 
radiation in a semiconductor. Independently, Ali Javan 
considered using a gas discharge as the amplifying medium 
for an optical maser, and published a specific proposed 
method for using a mixture of helium and neon [20]. With 
William R. Bennett, Jr. and Donald R. Herriott he set out 
to build a gas-discharge optical maser. They made mea 
surements of the excited state lifetimes and optical am 
plification under various conditions. Then they designed 
a laser structure with a discharge 1 m long, with extremely 
flat, very highly reflecting end mirrors inside the ends of 
the tube. John Sanders, visiting Bell Telephone Labora 
tories for eight months from Oxford University, proposed 
that an electrical discharge in pure helium might be used 
[21] and made some efforts to test the idea. 

For myself, I felt that it would be better to try to use a 
solid material that could be optically excited to provide 
optical maser action. This was very much in keeping with 
the strong emphasis on solid-state devices in Bell Labo 
ratories at that time. Although I knew nothing about the 
optical and luminescence properties of solids, we had 
mentioned the possibility of solid maser materials in our 
1958 paper. So this study provided me with a good reason 
to stop research on superconductivity and begin learning 
about luminescent crystals. 

One substance that was easy to start with was ruby, for 
that material was being extensively studied for solid-state 
microwave masers. Colleagues like Joseph Geusic had large 
stocks of ruby crystals with various concentrations of 
chromium ions in the aluminum-oxide crystal. I was in 
trigued by the fact that strong sharp-line fluorescence in 
the deep red could be excited by broadband light in the 
green and blue region of the spectrum. Thus one could use 



a broad-band pumping light to get relatively high gain per 
excited atom of a sharp-line emitter. 

However, in ruby all of the chromium ions are initially 
in the ground electronic state. In emitting fluorescence 
they return to this same state, and so the fluorescent light 
can be absorbed by the unexcited ions. As a result, it would 
be necessary to excite more than half of all the chromium 
ions before optical amplification would exceed the ab 
sorption losses. As no laser had ever been built I assumed 
that it meant it must be very difficult to make one. With 
out doing a serious quantitative analysis, I assumed that 
one would require a fourth energy level far enough above 
the ground state so that it would be nearly empty at the 
operating temperature. Then as soon as any atoms were 
excited to the upper state, amplification could be obtained 
by stimulating them to emit to this empty final level. Be 
cause the chromium ions in ruby lacked any such fourth 
level, this did not seem a promising material for laser ac 

Nevertheless the spectrum of ruby had some intriguing 
features that seemed worth studying. The theory of the 
spectra of ions like chromium in crystals was fairly well 
developed by that time, especially from the work of S. 
Sugano and Y. Tanabe in Japan [22]. The theory explained 
only the two strong red "R" lines, but there are many 
weaker lines within a few hundred angstroms further to the 
red of these. These satellite or neighbor lines had been 
known for about fifty years but had never been explained. 
I thought at first that they might arise from the crystal 
lattice vibrations and thus might give information about 
those modes of vibration. However my technician, George 
Devlin, noticed that the intensity of these lines varied from 
sample to sample. We soon found, with the collaboration 
of Darwin L. Wood, that the intensity of the neighbor lines 
increased rapidly as the chromium concentration was in 
creased. Thus we were convinced that the neighbor lines 
arose from pairs of adjacent chromium ions, whose energy 
levels were split by exchange interactions and we published 
this finding in collaboration with Albert M. Clogston who 
analyzed the theoretical aspects [21]. The lines were spread 
out enough to give us hope that for near-neighbor pairs the 
exchange-splitting might produce the fourth level we 
wanted for the lower state of a laser. I pointed out the 
possibility of getting laser action in dark ruby at one of the 
satellite wavelengths, at the first Quantum Electronics 
Conference in September 1959 [23]. We were encouraged 
by the fact that at low temperatures a crystal of dark ruby 
showed strong emission but little absorption at some of 
these wavelengths. I even made a brief try at getting laser 
action from a rod of dark ruby using a small flashlamp, but 
that was not sufficient and I returned to trying to analyze 
the neighbor-line spectrum of ruby. 

Others made more serious attempts to achieve operation 
of an optical maser. At Bell Telephone Laboratories, 
Geoffrey Garrett and Wolfgang Kaiser investigated rarer 
earth ions in crystals, looking for a four-level system that 
could be energized by a bright lamp. At TRG, Incorpo 
rated, a group including Gordon Gould and Richard Daly 
studied both eases and solids. 


Fig. 3. A. L. Schawlow with an early laser using a dark ruby rod, cooled 
by liquid nitrogen. 

But the first success was achieved by Theodore H. 
Maiman at the Hughes Aircraft Company's research lab 
oratory in Malibu, California. Maiman had worked on 
microwave solid-state masers using ruby, and his laser used 
a rod of pink ruby. A careful quantitative study convinced 
him that a flash lamp could excite enough ions to give laser 
action in pink ruby. He succeeded in demonstrating 
stimulated emission in ruby and announced the results in 
July, 1960 [24]. 

A number of scientists at Bell Telephone Laboratories 
then pooled their resources and used optically-pumped 
ruby crystals to confirm the predicted properties of laser 
light [25]: directionality, monochromaticity, and coher 
ence, as well as the high intensity that Maiman had re 
ported. They also found that the laser flash was composed 
of many short spikes, each lasting about 1 us. 

Before the end of 1960, no less than four other lasers 
were operated. Unknown to me, Peter Sorokin at IBM 
Research Laboratory had also been studying four-level 
ionic systems in crystals and, with Mirek Stevenson, he 
obtained laser action both from trivalent uranium ions and 
from divalent samarium ions in calcium fluoride [26], [27]. 
These were the first operating four-level lasers, but they 
were very soon followed by another. 

In November 1960, George Devlin and I tried again for 
laser action in the satellite lines of dark ruby, using the 
same rod as before but with a larger flashlamp (see Fig. 3). 
We obtained oscillation at 701.0 and 704.1 nm, in addition 
to the R line at 694.3 nm. At low temperatures, the satellite 
lines had the lower pumping requirements as expected 
since they were in a four-level system with an empty lower 
level. At just about the same time, Irwin Wieder and Lynn 
R. Sarles of Varian Associates also observed stimulated 
optical emission in the satellite lines. By coincidence, both 
our papers and theirs arrived at the Physical Review office 
on the same day, December 19, 1960 [28]-[29]. 

But even before then Javan, Bennett, and Herriott had 
achieved laser oscillation in their helium-neon electrical 
discharge. Theirs was not only the first gas discharge laser, 
but also the first continuous-wave laser [301. It operated 



at several wavelengths around 1.15 tan in the near infrared. 
In 1962, A. D. White and J. D. Rigden (31] found that the 
tame gas mixture would oscillate at 632.8 nm in the visible 
if mirrors designed for high reflectivity in the red rather 
than infrared region were used. 

By the end of 1960, five different kinds of lasers had 
been operated. Pulses with peak power in the kilowatt 
range had been demonstrated, as well as low-power con 
tinuous operation. Already the range of wavelengths 
spanned a range of 3.6:1, from ruby's 0.69 um to calcium 
fluoride: uranium's 2.5 ^m. From then on the progress has 
been increasingly rapid, with many new materials and 
great extensions of the wavelength and power outputs both 
continuous and pulsed. Quite marvelous and unexpected 
things have been discovered. Yet I cannot help thinking 
that even greater surprises may lie in the future. There are 
so many things that we can imagine but cannot do eco 
nomically or even cannot do at all. Quantum electronics 
has attracted some of the keenest and most original minds 
of our generation and they are continually making sur 
prising discoveries. As a result, the subsequent history of 
lasers is already much longer than these early beginnings. 

At the time when we wrote our 1958 paper, Townes and 
I were convinced thpt an optical maser could be made. But 
we were surprised to find how simple the first lasers turned 
out to be. Indeed many people since then have wondered 
why lasers were not discovered twenty or thirty years 
earlier, long before microwave masers. The techniques 
were available then, but the ideas were not Every scientist 
was trained to view the world as close to being in equilib 
rium. Really radical departures from equilibrium would 
be needed for stimulated emission to dominate, and that 
seemed unthinkable. However in microwave and radio- 
frequency spectroscopy, the quanta of radiation are very 
small, and so molecules or nuclear spins can only absorb 
small amounts of power before being strongly saturated. 
Thus large departures from equilibrium were observed 
without being sought, and researchers had to become very 
conscious of stimulated emission. Thus minds were pre 
pared to generate the clever ideas that led to masers, and 
eventually to lasers. It was understanding and ideas that 
were needed, more than techniques. Fortunately, scientists 
were able to undertake wide ranging studies of matter 
under unfamiliar conditions. They were thus led to new 
insights and from that to- the radically novel devices we 
now know as masers and lasers. 


[1] W. E. Lunb, Jr., and R. C. Retherford, "Fine itructure of the hy 
drogen atom*, Part I." Phys Rev., vol. 79, p. M9, 1950 (remark on 
p. 570). 


(2] A. Einstein, "On the quantum theory of radiation," Phyt. Zeu , voL 
18, p. 121, 1917. 

[3] R. Ladenberg, "Investigation* on the anomalous dispersion of ex 
cited gases; Part I, Test of the quantum-theoretical dispersion 
formula," Z. Physik, vol. 48, p. 15, 1928. 

[4] E. M. Purcell and R. V. Pound, "A nuclear spin system at negative 
temperature," Phyi. Rev., vol. 81, p. 279, 1951. 

[5] J. Weber, "Amplification of microwave radiation by substances not 
in thermal equilibrium," Trans I.R.E. Profetiional Group on 
Electron Device*, vol. PGED-3, June 1953. 

(6] J. P. Gordon, H. J. Zieger, and C. H. Townes, "Molecular microwave 
oscillator and new hyperfine structure in the microwave spectrum 
of NH 3 ," Phyi. Rev., vol. 95, p. 282, 1954. 

[7] N. G. Basov and A M. Prokhorov, " Application of molecular beams 
to the radio spectroscopic study of the rotation spectra of mole 
cules," Zh. Ektp. Theo. Fiz., vol. 27, p. 431, 1954. 

[8] N. G. Basov and A. M. Prokhorov, "On possible methods of pro 
ducing active molecules for molecular generator," Zh Ektp. Theo. 
Fiz.. vol. 28, p. 249, 1955. 

[9] J. Combrisson, A. Hpnig, and C. H. Townes, "Use of electron spin 
resonance for a microwave oscillator or amplifier," Comptes 
Renduet Acad Sci. Paris, vol. 242, p. 2451, 1956. 
(10] N. Bloembergen, "Proposal for a new type solid state maser,'' Phys. 

Rev., vol. 104, p. 324, 1956. 
(11] H. E. D. Scovil, G. Feher, and H. Seidel, "Operation of a solid state 

maser," Phyt. Rev., vol. 105, p. 762, 1957. 

(12] A. L. McWhorter and J. W. Meyer, "Solid state maser amplifier," 
Phyt. Rev., vol. 109, p. 312, 1958. 

(13) G. Makhov et a/., "Maser action in ruby," Phyi. Rev , vol. 109, p. 
1399, 1958. 

(14) Charlotte E. Moore, Atomic Energy Levels. VS. National Bureau 
of Standards Circular 467 (1949, 1952, and 1958). 

[15] A. Eucken and K H. Hellwege, Eds., Landolt-Bomstein Tables VoL 
1, Atoms and Ions. Berlin: Springer Verlag, 1950. 

(16) A. C. G. Mitchell and M. W. Zemansky, Resonance Radiation and 
Excited Atoms, Cambridge University Press, 1934. 

[17] A. G. Fox and T. Li, "Resonant modes in an optical maser," Proc. 
I.R.E., vol. 48, p. 1904, 1960. 

(18] G. Boyd and J. P. Gordon, "Confocal multimode resonator for 
millimeter through optical wavelength masers," Bell Syst. Tech. 
J., vol. 40, p. 489, 1961. 

[19] A. L. Schawlow and C. H. Townes, "Infrared and optical masers," 
Phys Rev., vol. 112, p. 1940, 1958. 

(20) A. Javan, "Possibility of production of negative temperature in gas 
discharges," Phys. Rev. Lett., vol. 3, p. 87, 1959. 

[21] J. H. Sanders, "Optical maser design," Phys. Rev. Lett., vol. 3, p. 
86, 1959. 

[22] S. Sugano sjid Y. Tanabe, "Absorption spectra of Cr 3 * in AljOj; Part 
A Theoretical studies of the absorption bands and lines," J. Phys 
Soc. Japan, vol. 13, p. 880, 1958. 

[23] A. L. Schawlow, D. L. Wood, and A. M. Clogston, "Electronic spectra 
of exchange-coupled ion pairs in crystals, ' Phys. Rev. Lett , vol. 3, 
p. 271, 1959. 

[24] T H. Maiman, "Optical maser action in ruby," British Communi 
cations and Electronics, vol. 7, p. 674, 1960; Nature, vol. 187, p. 493, 

[25] R. J. Collins et ai, "Ph Coherence, narrowing, directionality, and 
relaxation oscillations in the light emission from ruby," Phys Rev. 
Lett., vol. 5, p. 303, 1960. 

[26] P. P. Sorokin and M. J. Stevenson, "Stimulated infrared emission 
from triva'ent uranium," Phys. Reu. Lett., vol. 5, p. 557, 1960. 

[27] P. P. Sorokin and M. J. Stevenson, "Solid-state optical maser using 
divalent samarium in calcium fluoride," IBM J. Res. Develop., vol. 
5, p. 56, 1961. 

[28] A. L. Schawlow and G. E. Devlin, "Simultaneous optical maser ac 
tion in two ruby satellit lines," Phys. Rev. Lett., vol. 6, p. 96, 1961 

(29) I. Wieder and L. R. Sarles, "Stimulated optical emission from ex 
change-coupled Ions of Cr+++ in AbOa." Phyt. Rev. Lett., vol. 6, 
p. 95, 1961. 

[30] A. Javan, W. R. Bennett, Jr., and D. R. Herriott, "Population in 
version and continuous optical maser oscillation in a gas discharge 
containing a He-Ne mixture," Phys. Rev. Lett., vol. 6, p. 106, 1961 

[31] A. D. White and J. D. Rigden, "Continuous gas maser operation in 
the visible," Proc. I.R.E., vol. 50, p. 1697, 1962. 


NEVER TOO LATE - Communication With Autistic Adults 

Aurelia T. Schawlow and Arthur L. Schawlow 
849 Esplanada Way, Stanford, CA 94305 

Proceedings of the NSAC (now Autism Society of America) National 
Conference, July 1985 


Two years ago, at the age of 27, our son was essentially without 
speech and his only means of communication was with gestures. As will be 
described, he is now able to communicate anything he wants to say, by 
using a keyboard device. 


When our son Artie was small, he displayed the symptoms we now know 
as autism. But even the name "autism" was only about a decade old then, 
and few people knew it. Even if they did, there was no effective treatment 
and no school classes for him. We sought help everywhere, and often we 
thought that some time in the future something might be discovered or we 
would find someone with ideas that would have helped him if we had 
known it in time. But we made a conscious decision that we would at all 
times do the best we knew, and not regret later what we did not know. We 
kept on searching, and trying, and at last he has made progress at an age 
when many parents are no longer struggling. After all, most of us keep 
learning throughout our lives. Art was 55 when he bought his first 
microcomputer (an Apple I!). So we are happy to report that it isn't too 
late, and our son in his mid twenties has learned how to communicate. 


He was very withdrawn and unreachable. From age eight he lived at 
Clear Water Ranch, and from about 10 to 14, with Mrs. Grace Turner in a 
6-boy group home in Cloverdale. Those were relatively good years for him 
and he learned some living skills. Mrs. Turner brought him to Stanford for 
some trials on Dr. Colby's talking typewriter, but he did not take to it. 
At adolescence, people became afraid of him, because he was big and 
strong and would have occasional tantrums, even though he never hit 
anyone. Eventually we could find no place that would take him but the 
state hospital, which promised various training and vocational programs. 


But the promised programs somehow never materialized. Instead, they 
drugged him with antipsychotics despite our vigorous protests. We kept in 
close touch, with weekly visits, but he was too doped to do anything. 
Eventually, when the adverse side effects of these drugs became apparent, 
we obtained a court order of conservatorship, which specified our right to 
approve his medical treatment, and the drugs were stopped. Years had 
been wasted, and his behavior had deteriorated somewhat in the chaotic 
and violent conditions of the hospital. But he was now much warmer and 
responsive, and wanted to be with us. 


A behavioral specialist suggested that we try teaching him sign 
language, and we hired a sign language teacher to go in and work with him 
at the hospital. He would sit at a table with her, and make signs for such 
things as candies and cookies, and would receive a little of the named food 
when he made the right sign. He also learned a few other signs, such as bed 
and eat. In a way, this was a failure because few of the staff knew sign 
language, so that he had really no opportunity to use it for any practical 
purpose. In another sense it was very important, because for the first time 
he would sit and work with someone who was trying to teach him. 


We also found a very good teacher, experienced with autistic children, 
who was able to get him to recognize some letters on cards. She had Artie 
make signs for words printed on cards. It was suprising to us that he could 
do it at all, but sometimes could do it well. At other times he would just go 
through his repertoire of different signs. The teacher also found that he 
could even do beginning arithmetic by picking a number card for the sum 
of two small numbers, e.g. 2+3=5. Unfortunately, she soon got a better job 
and was not longer available. We tried other teachers, but he made no 
further progress with them at all. He was glad to see them, and willing to 
sit with them, but he was content to repeat the same simple things time 
after time. 


In December of 1981 we visited Stockholm for the Nobel 
presentation. We met there with Karin Stensland Junker. She is the mother 
of an autistic girl, whom she has told about in the well known book Child 
in a Glass Ball. She is also a clinical psychologist. Dr. Junker told us about 
a young man, age 24, who had been brought to her office. He looked 
typically autistic, and just sat there rocking and apparently ignoring 
everyone. Yet he had learned to communicate with a little device that 
looked like a calculator. It had an alphabetical keyboard, and printed the 


letters on a paper tape as they were typed. She asked him, for instance, 
"May I have some of your tapes?" He replied, in Swedish of course, "No." 
"Why not," she asked. "You can't read it when the sun shines" was his 
reply. This device uses thermal printing, and the tapes do fade quickly in 

This was exciting. How could Artie tell us something like that, even if 
he understood it? He had no way. We must get one of these devices and 
try it with him! But we didn't even know its name or who made it. 
Eventually we found that it was a CANON COMMUNICATOR, and that there 
was a distributor in Palo Alto, a mile or so from our house (2). We bought 
one, but it was a total failure. He would hit just a few keys over and over, 
like XXXXZZZZ, and would not type words. So we put it aside, and tried 
other things. 


Each had a cutout into which the letter would fit. We would say the name of 

the letter and the word illustrating it, as he put each one into the card. 


This device (3), made by Texas Instruments, uses a voice synthesizer 
to ask things like "Show me the red letter G," or "Show me the small letter 
r." We found that he knew the names of all the letters, lower case as well as 
capitals. He could even answer when the voice asked for "the letter for 
octopus," etc. 


We had him match pictures to pictures, and then pictures to words. We 
would print words on the back of cards, and have him match the word to a 
picture, or even give us a word on request. Another way was to have him 
put the words on the right picture on the board. 


We tried scrambling letters to arrange into a word, and he was able to 
spell his name and some other familiar words that way. Then we had him 
pick letters out of a box to spell a word. 


We obtained a child's book, the story of The Three Bears. Aurelia told him 
that she had learned to read by underlining a word, wherever it appeared. 
"Let's under line the word bear, wherever we see it." He was able to do that 
right away. Soon, we found that he could pick out any word on a page of 
that book. Even more surprisingly, he could pick out words from a 
magazine page, even one as difficult as the New Yorker. 



We had obtained the address of the parents of the Swedish boy 
who used the communicator, and had written to them asking how they had 
taught him to read. Their letter described what they had done, and we 
were much encouraged to learn that the way we were working with Artie 
was rather similar to the way they had taught their son. Their letter is 
reprinted in our article (1). 


At that time, Artie was living in a state hospital, and we could only 
work with him on visits. Conditions at the hospital were such that it was 
not practical to set up a computer and leave it there. However, the EPSON 
HX-20 computer was introduced, and it was battery operated and hardly 
bigger than a notebook. We found a way to program it in such a way as to 
induce him to hit just one key on a keyboard. A short program in the BASIC 
language would display on the screen a word, chosen randomly from a list 
in the program. A dash was shown under each letter of the word. Then 
nothing would happen unless he hit the right key to match the next letter 
of the word displayed on the screen. When the word was complete, it was 
printed out on the strip printer built into the computer. The first time we 
tried it, he did it eagerly for more than an hour until the tape ran out, and 
he stuffed the printer tapes into his pocket. 

We tried to get him to use the computer to select an alternative, e.g. 
steak or pizza, but without much success. 


By this time it was apparent that he knew the alphabet, and could 
recognize and spell some words. But he was not yet using words for 
communication. An article about our work up to that point (1) was 
submitted in August 1983, and concluded with "We are excited that our son 
is not too old to learn and is making progress The spark is there. Can we 
learn to fan it into flame, will it grow by itself, or will it fade 
away again?" But a few weeks later, progress was so dramatic that we had 
to write a postscript to the article. 


During the summer of 1983, a speech pathologist introduced us to 
communication boards. These were cards or even sheets of paper, on which 
words were printed. He could answer a question or choose something by 
pointing to the appropriate word. With a communication board, he could 
make a choice of foods, activities, or tools and materials for those activities. 


The speech therapist thought that he might require pictures on the board, 
but this was not at all needed. 

Around the same time, we made word cards for foods, then colors, 
etc, and had him put the cards on the object named. This, and the 
communication board, gave him practice in recognizing words, and gave 
him an opportunity to make choices by using words. 


The VOCAID (3) is another Texas Instruments device, similar in 
construction to the TOUCH AND TELL. However, it is programmed for people 
who have lost their voice and need to transmit essential messages, like "I 
AM COLD." Artie was able to use this immediately, and surprised us by 
stringing together two phrases to make a sentence. For instance, once he 
told us "I AM. ..UPSET." However, the range of choices is limited and he did 
not use it much. When he moved to a group home, at first the VOCAID was 
useful to let the staff know when he was upset or needed something. 


Most of these activities took place on outings from the hospital to a 
park. Afterwards we would finish with pizza and then ice cream. Art would 
get cheese pizza, because that was what he preferred. But since Artie was 
now making choices, we could let him choose what kind of pizza he wanted, 
by pointing to one of the words printed on a sheet of paper. Indeed, he 
unhesitatingly preferred sausage pizza. Then we had him confirm his choice 
by reproducing the chosen word on the COMMUNICATOR. He was willing to 
do this. 

A few weeks later, one of these outings was finishing with ice cream 
at a small shopping center. Then Artie waved his hand in a way that 
indicated vaguely he wanted something in a particular direction. So, instead 
of guessing, we took a chance and said "Come on out to the car and tell us 
what you want, on the COMMUNICATOR." We didn't really expect that to 
work, but he typed "SHOES," and indeed there was a shoe store there. So we 
took him in and bought shoes for him. 

AURELIA'S VISIT TO ARTIE on the following Monday. 

Two days later, Aurelia visited Artie, and went through his usual 
activities on the grounds of the hospital. But this time, she had him make 
his choices of activities by typing on the COMMUNICATOR, rather than by 
the communication board. Of course, these were all words he had seen 
often. But at the end, she asked him where he would like to go for a snack. 
He replied "GO TO MACDONALDS." "What would you like to eat there," she 
asked. "HAMBURGER..COKE..ICE CREAM" were soon forthcoming. After that, 
he wanted "PIZZA WHEEL" ( a nearby pizza parlor), and "SAUSAGE PIZZA." 


This was really working, and so he asked for and got a visit to a steak 
house for steak. It was getting late then, and she wanted to end the visit, 
but he typed "STAY YOUR TIME WITH ME." Then he added, not just once 
but three times, "I WANT TO GO HOME." So, although we were not ready for 
a visit, he came home, and remained for three weeks while arrangements 
were completed for a placement in a new group home. 


We tried to see whether Artie would use the COMMUNICATOR 
independently, and sometimes he would if he was especially eager. Most of 
the time, he wanted a hand on his for reassurance and help. We decided 
that getting his communications was more important at that stage than 
forcing him to be independent, and indeed he still wants a reassuring hand 
on his. We asked him when did he learn to read. He replied "WHEN I WAS 
TEN YEARS OLD." "Who taught you?" "GRACE (Turner)." "Why didn't you 
show it." "TOO HARD." "How is it that you can do it now," Aurelia asked. He 
smiled sweetly and replied "I LOVE YOU." He told us that he liked cowboy 
movies. "Why cowboy movies," we asked. "WIN THE WEST" was his answer. 
We learned that he liked the color red. One evening, he really surprised us 
by using the communicator to ask for "CHOCOLATE PUDDING." 

We found that Artie could print some without the keyboard. We 
learned this one day when Aurelia wrote down the list of tasks for the day. 
He likes to do chores around the house, but one day he grabbed the pen 
and printed VOTE. "Vote?" she asked. "VOTE WHAT WE MAY DO," was his 
reply. Then he crossed one of the jobs off the list. He does some printing 
now, but always wants another person's hand steadying the pen. 


At first, many of the staff did not believe in the Communicator, and 
did not use it with him. If someone tried half-heartedly, he would resist 
and conceal by just typing ZZZYXXXX, etc. We persuaded some of them 
to have him choose morsels of different foods with it, and they were able to 
do that, but only a few of them advanced any further. Now, however he 
does communicate fairly freely with several staff members, and with the 
teacher who works with him twice a week. Sometimes he has used the 
COMMUNICATOR to initiate things like "MAKE COOKIES." 

We visit him nearly every week, and he tells Aurelia a lot of things. 
We had noticed that the mother of the Swedish boy said that he never asks 
questions. So, one night at dinner, Aurelia asked Artie if he would like to 
ask any questions. His reply was a question: "WHY SHOULD I TYPE 
QUESTIONS?" "Because there might be something you would like to know," 
she said. His next question was "DO YOU LOVE ME?" On being asssured that 
she did, he asked "WHY CAN'T I LIVE AT HOME?" "Because there are things 


you need to learn here," she said. Then he asked "WHY AM I NOT LIKE 
HELEN (his sister)?" Again thinking quickly, Aurelia replied "Helen has a 
job." "I CAN GET A JOB," he said. "You can when you have learned some 
more," he was told. Since that time, he has often told Aurelia of his feelings, 
worries, and hopes. He communicates that he very much wants to be 
normal, and indeed anything that makes him feel more like a normal 
person is a strong motivator. 


Art also programmed the EPSON computer to ask Artie questions 
about addition, then multiplication and division. We found that he knew the 
multiplication tables and could add, subtract, and divide simple numbers. 


We asked him questions about text on a page after reading it silently. 
We found he could read even faster than we could, and we are fast readers. 
He must have been catching things at a glance all these years, when he 
never seemed to read anything. 


Artie has been gradually revealing so many things he knew, that we 
sometimes wonder whether he is really learning anything new. However, 
we have found a teacher, not experienced but persistent, observant and 
resourceful. At first, she -tarted on addition and he typed answers on the 
COMMUNICATOR. After a few lessons, he gave some answers to questions, 
in words and sentences. 

She started on multiplication with flash cards for 2X2, etc, and he 
seemed happy to work on that level. We told her that he already knows the 
multiplication tables. The next week she said, "You're right, he does." He 
told her that he did not know about carrying in addition, and she taught 
him that. Subsequently he learned, very quickly, about multiplying large 
numbers, long division, decimals and fractions, going through a grade level 
in about 3 months of 2 lessons or less per week. He does some printing with 
the teacher, mainly for answering questions. However, he has written some 
letters to us, with a little prompting from the teacher. 


Two young men in Ottawa, at the McHugh School (Stanley Tovell, 
Program Director) have learned to communicate with a SHARP 
MEMOWRITER, quite independently of our work. They are also using some 
computer programs and one of them is doing reading and arithmetic at a 
tenth grade level. Keyboards do not work for everyone in their classes. 


A 35-year old man, living at Camarillo state hospital who had learned 
to read earlier but was not communicating. His mother heard about our 
article, and since then has gotten communication from him with a 
typewriter. We learned at the NSAC Meeting that he is now using a 


Texas Instruments Computer TI 99-44 

We bought it about two months before Artie came home from the hospital, 
because it had a very striking program for learning the alphabet. But it was 
not practical to use at the hospital. Ly the time that he came home, it was 
clear that he was much past learning the alphabet. We set the 
microcomputer up at his new group home, and Artie did do some of the 
arithmetic programs with one of the staff members there. He was also able 
to handle the reading programs at the third grade level or so. The difficulty 
was that he found them too slow, and did not want to wait for the 
computer's response. 

Voice synthesizers. 

We tried both the VOTRAX TYPE 'N TALK and a borrowed voice synthesizer 
in the $3000 price range, but he resisted them. He was with his mother 
when Art was trying out the more expensive synthesizer. He told her "That 
sounds silly. I could learn to talk with one of those, but I want to talk by 
myself." As he always has, he occasionally says some words, but he is not 
able to use them at will for communication. 


You have to be interested in what he wants to say. It is important to 
make each step easy and rewarding. He has a good long attention span, but 
a short frustration span. His biggest problem seems to be an overwhelming 
shyness, like stage fright, that makes him afraid to try things and to reveal 
what he can do. Devices are very helpful, but the close, supportive, personal 
interaction is essential. 


Autistic adults can learn, just as normal adults can. It really is never 
too late. As for how we feel, we can only quote the Bible story of the 
prodigal son, and say that "our son who was dead is alive again." 


(1) The Endless Search for Help, by Aurelia T. Schawlow and Arthur L. 

Schawlow, in Integrating Hoderately and Severely Handicapped 


Learners: Strategies That Work, edited by Michael F. Brady and Philip 
Gunter, Charles Thomas Publishing Company, 1985. 

(2) CANON COMMUNICATOR is distributed by CANON U.S.A., and can be 

obtained from medical supply companies. 

(3) TOUCH 'N TELL and VOCAID are products of Texas Instruments. TOUCH 
'N TELL is found in toy stores, and VOCAID in medical supply stores. 






Strategies that Work 

Edited By 


With Linda Parnell, Technical Editor 
A Foreword by Roger J. Blue 

A Project of 
The Association for Retarded Citizens-Tennessee 


Springfield WHO* U.1A. 






Our son was born on March 21, 1956. That was about two weeks later 
than expected, and more than two feet of snow had fallen in New 
Jersey over the preceding weekend. There were some anxious hours, but 
eventually the snow did end and roads were cleared in time for the trip to 
the hospital. The birth was long and difficult, and was complicated by a 
deep transverse arrest that the doctor, busy with another patient, overlooked 
for several hours. But our son was so beautiful and lively; our first child! We 
named him Arthur (after his father and paternal grandfather) Keith. We 
have always called him Artie. 

At the time. Art was a research physicist at Bell Telephone Laboratories 
in Murray Hill, New Jersey, and Aurelia was choir director of the First 
Baptist Church in Morristown. We had a new house in Madison, and Artie 
was the center of our life. Before long, he was joined by two sisters, Helen, 
born in July, 1957, and Edith, born in November, 1959. Artie seemed to us a 
perfect baby, ahead of the books' predictions in physical development like 
turning over, sitting up, standing and walking. Yet, if we had been more 
experienced parents, we might have known that he was neither as demand 
ing nor as responsive as most children. He was quick to learn things by 
himself, but not at all easy to teach. 

Around the age of one, he began to say a few words, but then he stopped. 
He gradually became more withdrawn and often seemed content to amuse 
himself by listening to music or playing with toys. 

Becoming concerned, we began what was to become an endless search for 
help. An old friend, a distinguished European-born neurologist, told us 
that our son had "a mathematician's personality" and would eventually start 
to talk. At that time. New Jersey had no medical school. Even though we 
lived in an affluent suburban area, there were few specialists familiar with 
the more unusual childhood conditions. We did find a pediatric neurologist 

The Schawlows we parents of an autistic ion. Ankur Sckaelov received his Ph.D. from the University 
of Toronto. He currently is Professor of Physics at Stanford Univenity. He received a Nobel priie in 
Physics in 1901 for his contributions to the development of laser spectroscopy. Aunln Skarlow received her 
M.A. from Columbia and is a musician, singer, and choral conductor. 

6 Integrating Moderateiv and Severely Handicapped Learners 

who, although extremely busy, eventually did examine our son. She decided 
that he had petit mal epilepsy and prescribed a drug for that. Almost 
immediately, it was apparent to us that the drug was not helping, and that 
he was becoming even more withdrawn. Moreover, he became incontinent, 
so that he was no longer "acceptable" in a nursery school. In addition, there 
were occasional episodes when his face would suddenly turn purple, and he 
would have a far away look. We tried to get the doctor to see what was 
happening, but we could not even get our telephone calls returned much of 
the time. This was the first of several times that doctors blithely prescribed 
drugs and then refused to recognize harmful effects that were immediately 
evident to us. Another such incident occurred when Artie was about seven 
years old. A neurologist prescribed heavy doses of an amphetamine. We 
begged him to monitor the effects closely, but it was the same story. Perhaps 
he felt we must give the drug enough time to act. We think that he was 
looking for some kind of anomalous reaction of the drug, but it was quickly 
and painfully evident that the drug was doing just what amphetamines 
usually do. Artie lost his appetite, and would only eat a very few things. His 
stereotypic behavior became even more persistent. Then, too, he was awake 
until 1:00 a.m. night after night. 

The Search for Services 

By 1961. when he was five years old, it was apparent that there was no help 
to be had for him in our area of New Jersey, not even an appropriate school 
or day care program. Thus, when Art received an offer of a professorship 
from Stanford University, and we learned that parents there had set up a 
school for children like Artie, we decided to move. One of Art's colleagues 
in the physics department had a daughter who was similarly withdrawn and 
nonverbal, and his wife had been a leader in establishing the school. 

The first year at Stanford was a good year for Artie, and the school 
seemed to be something he enjoyed. But then the director of the school left 
for a better position, and things did not go well for our son under her 
replacement. Artie was not willing to participate in the group activities and 
would wander off by himself more often. We sought help from neurologists, 
which led us to the amphetamine incident recounted earlier, and from 
psychiatrists. The psychiatrists, although they would probably not be classed 
strictly as psychoanalysts, were influenced by that school of thought. Their 
approach was just to try to get us, the parents, to search our souls to find 
what terrible things we were doing wrong. Not only is this approach useless, 
but it is also destructive, because it makes the parents less, rather than more, 
able to cope with the difficult behavior of the autistic child. Also, that 
approach immediately puts a gap between the parent and psychiatrist. If the 


Our Son: The Endless Search for Help 7 

psychiatrist insists on treating the parents as his patients, he cannot work 
with them to help the child who is, after all, the person who needs help. 

By the time Artie was eight years old, it was apparent that we could not 
provide the teaching and companionship of other children that he needed. 
The public schools had nothing at all for him in those days. But we did find 
a residential setting, Clearwater Ranch Children's Home, which seemed as 
if it could provide a good environment for him in a rural area. We placed 
Artie in the home and visited him there weeklv. He came home for occa- 

sional visits. After a year or so, he was moved to the Clearwater Ranch Town 
House, in the small town of Cloverdale. There were six boys in the house, 
and it was run by a wonderful lady, Mrs. Grace Turner. She had spotted 
Artie at the ranch and asked for him because he had reminded her of a boy 
who had started to talk while in her house. Artie learned many things there 
and those were, on the whole, good years for him in which he gradually 
became less withdrawn. He did not really talk satisfactorily then, but he 
sometimes said phrases or sentences. Artie became able to do a number of 
household chores and took pleasure in performing them. 

However, at adolescence, several things took a. turn for the worse. Mrs. 
Turner was not able to continue with the Town House. Artie grew big 
enough so that he frightened some of the teenage girls who worked on the 
staff. Even though at that time he never harmed staff or other residents, the 
staff became particularly nervous when he began to have occasional tantrums. 
Eventually, they decided that Artie was too big to manage, and we had to 
find another place for him. 

We found another ranch and he moved there. He was immersed in a 
larger group and apparently did not get enough individual attention because 
he became more isolated and withdrawn. When he began tearing up clothes 
and sheets, this home decided that they could not manage him. However, he 
still had never attacked nor hit anybody. 

Hospitals and Teachers 

In desparation, we put Artie into a state hospital. It was in a convenient 
location, 17 miles from our home, and had spacious grounds. We were told 
about their various programs and workshops, and it looked like a reasonable 
choice. Besides, we had no alternatives, because there were then few group 
homes for autistic adolescents and adults. 

The hospital proved to be far worse than we feared initially. Somehow, 
the classes never materialized, or would get cancelled after one or two 
sessions because the person in charge was needed elsewhere, or for some 
other reason, or for no reason. Worse than that, the hospital relied on 
massive doses of antipsychotic drugs of the phenothiazine group (e.g., 

8 Integrating Modtrately and Severely Handicapped Learners 

Mellaril or Thorazine) for behavior control. They insisted on drugging 
Artie until he looked like a zombie. I don't think they had any idea of Artie's 
abilities; under those drugs he looked and acted really stupid and half 
asleep. The wards were quite chaotic with a lot of boys who would frequently 
hit others. We brought him home for visits almost every weekend in order to 
take him swimming, but under the drugs, it was difficult to teach him. 

We continually argued with the doctors and with the hospital authorities 
to reduce or eliminate the drugs. We were never told that the drugs were 
good for Artie, but rather that the staff wanted them, or that he needed a 
tranquilizer for such a violent environment. Not only did the drugs affect 
his behavior, but physical side effects became evident. Thorazine made his 
skin very sensitive to sunburn, and it was constantly irritated. Mellaril made 
it nearly impossible for him to swallow. He still has a habit of holding saliva 
in his mouth that originated when Mellaril prevented him from swallowing. 

Eventually, we learned of the very great danger of tardive dyskinesia. an 
irreversible condition that often follows prolonged treatment with these 
drugs. Sometimes the authorities would yield a bit to our entreaties and 
reduce the drugs; but if they had any trouble with his behavior, a higher 
dose would again be administered. His behavior did become rougher, a 
matter of sheer survival in that environment. At last, we found a newspaper 
report of a court decision that drugs could not be given to patients without 
their consent. When we showed that to the director of the hospital, her staff 
studied it and told us that we could not speak for Artie on that because we 
were not his guardians. We then went to the expense of getting a court order 
of limited conservatorship which specifically set forth our right to control 
his medical treatment. The hospital administration was furious, and tried 
several times to get rid of us and Artie. But somehow, once the drugs were 
gone, we found in Artie a warm and loving person, who clearly wanted 
attention and was open to learning. What a contrast from the remote and 
unreachable child we had known. 

We, of course, wanted Artie out of the hospital. We tried several times 
keeping him at home for extended periods. However, we could not find any 
appropriate program for him in our community, and it was too much for us 
to supervise him all day, every day. Since we couldn't manage to keep him 
occupied at home, we tried seeing what a teacher might be able to do at the 
hospital. A teacher who had some experience as a sign language instructor. 
but was working on a college degree to acquire credentials, began visiting 
Artie at the hospital to try teaching him sign language. It was pan of the 
plan from the beginning that signing might also help him to relax enough 
to produce some speech. She started with food words like candy, cookie, and 
apple. The correct sign, or an approximation, was rewarded by a bit of that 
delicacy. Somewhat to our surprise, he was happy to sit and work for an 

Our Son: The Endless Search for Help 9 

hour or so at a time on various signs. Although it did not seem easy for him, 
he did learn a number of signs including those for some articles of clothing 
and some familiar objects, and he made sounds with some of them. Most 
striking was the word "bed" which he would say clearly while making that 
sign. Sometimes surprising things came out, like "peanut butter." Apparently, 
the effort of making the sign helped to overcome his inhibition against 
speech. But neither then nor subsequently has he been in a situation where 
he could really use those signs for communication, and so he rarely does. 

What really seemed important was that he had acquired a taste for 
working at a table with a teacher for extended periods. While he was still 
working on the signs, we were able to hire an inspired teacher, Mrs. Joanne 
Glass, who began to work on recognizing letters, words, and simple arithmetic. 
Progress was exciting, but after a few months, she moved to a better job 
which did not leave time for working with our son. We hired students who 
kept up the human contact but did not have the skills to make much 

Learning and the Surprise of Technology 

Meanwhile, we continued to visit our son every week, and we kept up 
these visits even later when he moved to a residential home 65 miles away. 
In many ways, this house and the accompanying day program were great 
improvements over the hospital; however, the emphasis was on controlling 
behavior and. as far as we could tell, they did not take seriously the possibil 
ity of academic learning. Many of these things we did on our visits were not 
academic either, but we did use letter cards every week. He learned to 
recognize letter shapes by inserting them into the cards from which they had 
been stamped. Each time he inserted one, we would repeat the name of the 
letter and usually the word which accompanied it on the card (e.g., "L for 
lion"). However, we only began to realize what he had learned when we 
bought a Texas Instruments Touch and Tell 1 ". This device produces a 
synthesized voice that asks things like "Where is the red letter Q?" or "Can 
you find the small letter X?" Correct answers are given by pressing the 
appropriate letter on the device and are rewarded by a few notes of a tune 
and by the voice saying cheerily, "You found the small letter X." After a 
slightly timid start, it was soon evident that Artie knew all of the letters of 
the alphabet by name, upper, and lower case. He also had no difficulty when 
the synthesized voice asked him to "Show me the letter for king," or some 
other word. Artie had learned the alphabet. 

So he knew the alphabet, but how much did he really know about words? 
There are various packages of Word Lotto available with cards which bear 
pictures of familiar objects and their names, such as "umbrella" or "shoe." 

10 Integrating Moderately and Severely Handicapped Learners 

He could easily pick out any card asked for by name and match it with the 
right picture on the large card. Aurelia then printed the words on the backs 
of the small cards and asked him for the cards by name. The first week he 
succeeded in identifying the six cards presented to him and the next week. 
12 more. By then it was apparent that he could recognize any card she 
presented and was not just memorizing them at that time. 

Next, Aurelia tried reading a beginning level story book with him. It was 
a simple version of the old story about the three bears. Then she told him. "I 
taught myself to read by underlining words whenever I could find them. 
Let's see if you can find the word 'bear' and underline it." He was able to do 
that right away, and it was soon apparent that he could recognize any word. 
not just a list of words that he had been taught. He really had developed the 
idea of how to read. 

But how could he communicate what he was thinking? We were given a 
most exciting clue during our trip to Stockholm in December 1981. There 
we met Dr. Karin Stensland Junker, who is a renowned authority on autism 
and author of the book Child in the Glass Ball. This book is about her own 
autistic daughter. Dr. Junker told us that a young man, 24 years old. had 
been brought to her office a few months earlier. He appeared very with 
drawn and typically autistic, and sat seeming not to notice what was going 
on around him. Yet he had learned to communicate by using a calculator 
like device that printed out words on a paper tape. For instance, she asked 
him, "May I have some of your tapes?" He replied (in Swedish). "No." 
"Why not?" she asked. "Because it's no good when the sun shines" he said. 
The device uses a thermal printer, and the tapes fade when exposed to 
sunlight. Mats, as his family called the young man, understood that the 
tapes faded; now, at last, he could express it. How marvelous! Just imagine 
how frustrated he must have felt when he could not express his thoughts at 

We found out some months later that this device is a Canon Communica 
tor* 1 , which is sold in this country for about $600 by Telesensory Systems 
near our home in Palo Alto. We bought one, but our son would only type 
words if we guided his hand and mostly seemed to want to bang the keys 
randomly. Meanwhile, we were trying some of the other things described 
earlier. We got the address of the Swedish boy's parents and eventually 
received a letter telling how they had taught their son to read and type. We 
were excited because we found many similarities between what they had 
done and what we were trying. 

The Epson HX-20 portable microcomputer became available late in 
1982, with a full-size keyboard, a liquid crystal display, and a small printer. 
We wrote a program for this computer which would present either single 
letters or words on the screen with a series of dashes underneath, like: 

Our Son: The Endless Search for Help 1 1 

Viola ROnnlund 
Vikingsvttgen 26 
S-175 61 Jarf alia 

17-02 1983 

Mr. A. Schawlow 
Stanford University 
Stanford, California 94305 

Dearltr. Schawlow, 

Thank you for your letter of October of last year and I apologize 
for the delay in replying. It has taken a while to compile every 
thing and then to get it translated to English. I hope it will be 
of help to you. 

Here are some notes on Mats and how he learned to read and write 
with the aid of a typewriter and later to use his communicator. 
Mats' s sister, who is a teacher, and I, his mother, started to 
teach Mats a kind of unit reading. That was as early as 1967 . We 
were only able to teach him during his summer vacations and every 
second or third week when he came home to see us . 

We tried to make him point at pictures representing words which 
belonged to phrases he was to read later. We asked him about each 
picture and he seemed to understand us and pointed at the right 

The next step was to give him words . First he combined two- 
letter, and then three-letter words with the pictures. For the 
most part , he managed to match the right words with the pictures . 

Mats lived at home between 1970 and 1975 and we continued the 
way we had started - combining words with pictures . Gradually, 
he managed to put longer words, five-letter words, six-letter 
words , to the right pictures . We proceeded with short phrases , 
e.g., "The child is playing," "The rabbit is eating," and 
these he managed to place with the correct pictures . 

After this, Mats started making words from letters. I showed 
pictures of, for example, a girl, a boy, an animal, a house, a 
car, or a rose. We had mixed the letters and he chose the right 
ones to spell out the word suitable to the picture. We kept this 
up for about a year. Then he started spelling out two-word phrases . 
These phrases were gradually increased to five words . 

Some time later, we started reading books. I read aloud and Mats 
followed each line with his finger. After a couple of pages, we 
stopped and I asked him to show me where a certain sentence 

12 Integrating Modtratel\ and Severely Handicapped Learners 

appeared in the text . At about this time , I encouraged Mats to 
practice writing the letters of the alphabet by hand. 

Later on we started practicing with an electric typewriter. Mats 
tried to answer questions from a book for children in second and 
third grade (8-9 year olds) . The questions were , for example , "A 

lemon is not sweet but . " Mats had to type out the missing 

word on the typewriter. Another simple example was to answer a 
question such as , "this animal you get milk from.' In most cases , 
he managed to type the correct answer. 

We continued the reading - now going one step further - both of 
us reading quietly to ourselves . After having read three or four 
pages , I asked who the passage was about and what sort of actions 
were being carried out . He progressed very well and his spelling 
was remarkably good considering he had not been practicing diffi 
cult words. We continued with this type of reading and are doing 
so at present . By now we have read a great number of books . Nowa 
days he uses his communicator to answer our questions. The 
advantage is that he can always carry the communicator he got 
three years ago. 

Mats has typed several letters to friends and relatives on his 
electric typewriter. However, I have always to dictate these let 
ters or nothing would be done - he finds it difficult to take the 
initiative himself. He can also write by hand and he has written 
some letters in this way, though I must hold my hand lightly on 
his . Right now I am trying to make him write by hand without any 
support . Every now and then it works . 

When it comes to reading and writing, we are hoping that he will 
start asking us questions. We feel that this would be a great step 
in our mutual contact and communication. We so much want him to 
take an interest in the world around him instead of turning inward 
into himself, but we do not know how to help him in this matter. 

These are some of the methods we have used with Mats and for 
the most part , we have had very encouraging results . I do hope 
our efforts can be of help to you and that you will keep in con 
tact with UB and let us know if you have any success . We wish you 
all the good fortune and patience when helping your son. 

Kind regards 
( signed) Viola and Magnus ROnnlund 


Our Son: The Endless Search for Help 13 


The program was written to ensure that nothing was entered if he hit several 
keys at the same time. He had to hit the right key, and no others. Artie could 
bang at the keys all he wanted, but nothing would happen unless he hit the 
right letter, first B and then O, O, and K. Each time a correct letter was 
entered, the computer would emit a brief tone. After the word was finished, 
the computer would play four notes of music and print the word on the little 
printer. This worked and Artie enjoyed it. although he still wanted a 
parent's hand on his to guide him. Sometimes, he would do nearly all of the 
guiding by himself, but he would rarely do it alone. Later, we wrote another 
program that displayed and printed larger characters, up to seven on a line 
rather than the twenty of the computer's regular character set. This was an 
improvement, but he still wanted a hand on his. 

Right now, Artie's primary problem seems to be motivation. He has not 
seemed to realize that he can communicate with words. We are working on that 
now. Instead of emphasizing the typing, we are getting him to point at YES or 
NO or to circle the desired word. He is beginning also to use a communication 
board to pick out which of his activities, or which food, he wants by pointing to 
a word on a board. We learned in Orlando, Florida, last year about one teenage 
autistic boy whose behavior improved dramatically when he was given a com 
munication board to describe his moods. When he came to school, he could 
point out whether he felt sick, angry, or tired. A communication board is quick 
and direct, but the range of choices is necessarily limited. However, it does 
seem to be working for Artie and gives him a verbal way to tell us some things. 
We hope that his success with it will soon carry over into answering questions 
by typing a word. Then we will return to the Canon Communicator* which he 
can carry with him and which might eventually be used to express any thought. 

To teach him to type, we have used the Epson microcomputer, (although 
it is far from ideal) because we had to use a portable computer. Since he is in 
the state hospital, which is thoroughly chaotic we can not set up and us